In late August, Cleveland Indians reliever Oliver Perez entered a game in the sixth inning to face a left-handed hitter. It was his 55th appearance of the year, and with that his option for 2020 vested: Perez will be paid $3 million next season to face lefties.

It’s fortunate for Perez that the deal was signed when it was, late last January. Two weeks later, ESPN’s Jeff Passan reported that in 2020, Major League Baseball would likely require pitchers to face three batters, or get the final out of an inning, before they could be removed.

Perez had 22 outings in 2019 that would be illegal under these new rules — let’s call them Ollies, after Perez — which was the most of any pitcher in baseball. Without those Ollies, his 2020 option might never have vested. And without those outings going forward, his actual value to a modern bullpen becomes much more speculative.

This makes Perez perhaps the clearest victim of the new rule, along with a few lefty-specialist contemporaries: Andrew Chafin, who had 19 Ollies, after leading the majors with 22 in 2018; Alex Claudio, whose MLB-leading 83 appearances included 17 that will soon be outlawed; and Adam Kolarek, whose 15 regular-season Ollies were supplemented by three more in the National League Division Series.

There were about 650 such outings in 2019, according to Elias Sports Bureau, which is just under 4% of all relief appearances — a minor adjustment, in the large view of things. But for individual players, it’s the small view of things that matters, and a pitcher such as Perez must feel under threat.

So let’s consider that small view: Will Oliver Perez survive in this world of mandatory longer outings, or was that vesting option the final bit of good news in a long and nomadic career?

In each of those 22 Ollies that Perez had last year, one of three things would have happened under the new rules: Perez would have come into the game earlier, he would have stayed in the game later, or he wouldn’t have appeared at all. Here’s our best guess of what would have happened in each of them. Anything in regular text is what actually happened; anything italicized describes our most likely hypothetical; and each date links to the box score and game log.

March 28: Perez, having faced lefty Max Kepler and switch-hitter Jorge Polanco, would have been allowed to face Nelson Cruz, representing the tying run, with one out. He would then have been left in to face lefty Eddie Rosario.

April 1: After allowing a score-tying double to switch-hitter Yoan Moncada, and forcing the White Sox to pinch hit righty Ryan Cordell for lefty Daniel Palka, Perez would have been left in for Cordell and Jose Abreu. If he had retired Cordell, he would have intentionally walked Abreu. Here we already see one of the big liabilities of lefty specialists under this new rule: It’s not just that they have to face right-handed batters, but that the right-handed batters that follow each team’s best left-handed batter are usually very good right-handed batters. So if Perez’s manager wants him to face the Polancos and Moncadas of the world, he’s also exposing him to the Cruzes and Abreus.

April 16: Perez would have entered the seventh inning one batter earlier, to face right-hander Tom Murphy before going after lefties Dee Gordon and Mallex Smith with a three-run lead. This would have meant a slightly quicker hook for the starter, Shane Bieber, who had completed the sixth but was allowed to go back out for the seventh until he allowed a runner.

April 26: After allowing a two-out single to lefty Michael Brantley — with a one-run lead against Houston — Perez could have been left in to face righty Carlos Correa, as the potential go-ahead run. He then would have stayed in to face lefty Josh Reddick, either that inning or the next.

May 3: With two outs, I think we’ll still see managers gamble on the reliever’s ability to get one out. It is a gamble, though, and in this game we see the potential cost: Perez needed to get lefty Dan Vogelbach to end the inning in a tie game. He didn’t, and under the new rules he would have been stuck facing power-hitting righties Edwin Encarnacion — to whom he’d allowed a homer a few days earlier — and Domingo Santana. The other option, which seems more likely, is that Perez would have actually started the inning, facing lefty Dee Gordon and righty Mitch Haniger before Vogelbach came up.

May 7: Never would have appeared. A right-hander would have faced switch-hitter Yoan Moncada instead.

May 20: After retiring lefty Matt Olson — trailing by three in the seventh — Perez would have faced righty Stephen Piscotty and switch-hitter Jurickson Profar, who is worse against left-handed pitching.

June 11: Perez probably comes in one batter earlier, to face lefty Derek Dietrich with two outs and the score tied. If necessary, he would have stayed in one batter later, to face Yasiel Puig, but the odds are he would have retired one of the first two batters he faced to get out of the inning.

June 22: Never would have appeared.

June 25: Perez probably stays in after his two batters to face Hunter Dozier with a two-run lead and nobody on and Jorge Soler on deck. Would have been a little scary, especially if one of the two lefties he retired had reached base, making Dozier the tying run.

July 2: Really tough one. He entered with a four-run lead, the bases loaded and nobody out, to face a good switch-hitter and a good lefty. Probably would have stayed in to face the right-handed Dozier, representing the go-ahead run. But might never have appeared.

July 12: Perez would have intentionally walked Nelson Cruz, having failed to end the inning against his two intended batters.

July 14: Perez would have faced Nelson Cruz with the bases loaded and two outs with the score tied. Yikes! It’s possible his outing would have begun two batters earlier, to avoid any chance of him facing Cruz, but that would have meant replacing the starter earlier, and facing right-hander Jonathan Schoop. That would have been the better scenario in retrospect, but would not have been easy to anticipate.

Aug. 3: Perez would have stayed in to face righty Justin Upton and, if necessary, lefty Kole Calhoun with a four-run lead in the eighth.

Aug. 8: Perez — who in real life faced only Eddie Rosario — would have been brought in three batters earlier, to face Max Kepler and Jorge Polanco, as well as righty C.J. Cron, before Rosario. It might have kept him from being able to pitch the next day, which he did in real life.

Aug. 11: Perez would have been left in to face Miguel Sano with two out and nobody on, with a two-run lead.

Aug. 18: Perez would not have appeared. A right-hander would have faced switch-hitting Didi Gregorius with the bases loaded instead.

Sept. 7: Perez would have stayed in to face Mitch Garver a right-hander who had been sandwiched between Max Kepler and Jorge Polanco in the Twins’ lineup — and then Polanco and lefty Eddie Rosario. Kepler/Polanco was the standard Perez matchup: He faced each of them eight times last year, three more times than he faced any other batter, and four of these 22 Ollies were exactly Kepler and Polanco and then Perez’s exit.

Sept. 11: Probably would have been brought in to start the inning with a one-run lead, facing lefty Brian Goodwin and righty David Fletcher before his targeted batter, Shohei Ohtani. Or he might have come in for Ohtani, as he actually did, and just stayed in to face Albert Pujols.

Sept. 20: Probably would never have appeared. Carlos Carrasco would have faced Bryce Harper with the three-run lead, rather than let Perez face Rhys Hoskins and a pinch hitter after Harper.

Sept. 21: This time, I think he would have faced Harper. It was earlier in the game, and less likely the Phillies would use a pinch hitter for Jay Bruce after Hoskins. So Perez would have stayed in to face Hoskins and Bruce.

Sept. 22: With a nine-run lead, Perez would have been left in to face one more batter, Jose Pirela.

So the takeaway isn’t necessarily “Oliver Perez will lose a ton of outings,” but, perhaps, “Oliver Perez is going to have to face a bunch more right-handers.” Indeed, if our best guesses are correct, Perez won’t be used less; he’ll be used more, to face 17 more right-handers and six more left-handers. There are a lot of left-handed hitters in the game (or switch-hitters who do better against right-handed pitchers), and an opposing manager can’t keep all of them three spots away from each other.

So, for instance, consider that July game against the A’s: The lefty Olson has a big platoon split, and he’s followed by the righty Piscotty, who has a big platoon split, followed by the switch-hitter Profar, who has a small platoon split. In a perfect world for the defense — the one we’ve lived in for about three decades — the manager goes to a lefty specialist for Olson, then a righty for Piscotty, and leaves the righty in against Profar. Using the hitters’ splits as our guide, those three hitters would have an expected OPS of around .730.

That won’t be allowed anymore, so the manager will have to decide whether to use a right-hander for all three or a left-hander for all three. And the left-hander is the better option: Lefty hitters tend to have bigger platoon splits than righty hitters. And Olson is the batter the manager is especially targeting, the most dangerous of the trio. So those three A’s hitters’ expectations against:

• All left-handed pitchers: .760 OPS

• All right-handed pitchers: .790 OPS

Perez’s utility to the staff is reduced a bit under the No Ollies rule. But he’s still more valuable in that situation than a right-hander alone.

So if we know Perez is still going to be used in nearly as many games, the question is how much worse his numbers will get if he’s facing more right-handers. Perez faced 55% lefties last year, 45% righties. Under the hypothetical scenarios above with the No Ollies rule, he would have faced 52% lefties and 48% righties. Using his three-year platoon splits, we can estimate how many more runs he would have allowed last year if, instead of 55/45, it had been 52/48. The answer is: Only one-half of a run! Hardly anything, really.

But wait: Facing more righties makes Perez slightly less valuable, but — since he’s still a pretty good pitcher — pitching more innings would make him slightly more valuable. If we adjust him from 55/45 to 52/48, but also increase his usage by 23 batters, then we’d estimate he’s about a half-run more valuable than he actually was. It’s an Olliesance! Oliver Perez is just getting started! The victims of this rule might not actually be the lefties who seem directly threatened by it, but (in a smaller, more dispersed way) the right-handers who are going to lose a little bit of work because the Olliers need to finish their innings.

Maybe. That’s certainly one way this could play out. But it depends on three things:

1. How risk-averse will managers be? The most representative Ollie situation from last year was probably the first one: facing the Twins with a two-run lead, brought in to face lefty Max Kepler and switch-hitter Jorge Polanco, who is better against right-handed pitching. Nelson Cruz would have been the third hitter in that sequence, but Perez never had to face Cruz last year. Under the new rules, he would. As a manager, the math still seems simple enough: There are two batters you want the lefty in for, so you accept the one batter you don’t. And it works if he gets Kepler and Polanco out. But if he doesn’t, then Cruz would bat with runners on, representing the tying or go-ahead run, in a spot to really do damage. It feels easier to justify letting a right-hander face Kepler with a two-run lead than letting a lefty face Cruz as the tying run, which the manager might be committing himself to when he puts a left-hander in. That, too, is how you’d get the situation we imagined in the July 14 game: Cruz up with the bases loaded in a tie game against a lefty specialist. Managers might decide it’s not worth the risk.

2. To avoid that, will managers be more proactive about getting their lefties into the game a little bit early, perhaps even for the final batter of a previous inning? In a number of the Ollies above, the Ollie could have been avoided by bringing Perez into the game one or two batters earlier, sometimes even to face a lefty. A manager might do that to avoid having to leave him in for the punishing right-handed batter further down the line. It would be a good habit to develop. But it would often mean a shorter outing from a top starter — which isn’t totally without cost to the team — and it would always require a bit of foresight.

3. Will Perez (or his lefty peers) be good enough? As Perez has pitched in the past three years, the answer is yes. But there would be a big gap between the exposure to right-handed batters that a good lefty would face and the exposure that a bad lefty might face: If Perez comes in with two outs and gets his targeted opponent, the inning would end and he could leave the game. If he doesn’t, he might have to face Nelson Cruz with the bases loaded in a tie game! Failure would now compound. So while almost every team had a lefty specialist last year, it might be that by the end of 2020 there will be only 15 — all of them heavily used — but that the mediocre ones would wash out and some teams would just do without. To keep a healthy workload, a lefty will need to have his manager’s trust, more than ever.

In early December, the A’s non-tendered Ryan Buchter, a bad omen for Perez and those like him. Buchter has four seasons in the majors and an ERA under 3.00 in each of them; last year, he led the A’s with 11 Ollies. As Susan Slusser wrote in the San Francisco Chronicle, the move was “in part because of the anticipated three-batter minimum next season.” The A’s preferred two other lefty relievers — Jake Diekman and T.J. McFarland — who have been worse than Buchter overall, but have smaller platoon splits. In other words, they might not be as good in the old way of doing things, but they can be trusted (a little bit) against Nelson Cruz with the bases loaded in a tie game.

Until we’ve seen this play out for a few years, a lot of this comes down to perception, and that’s what’s at stake for Perez and his peers this year: Can they avoid those Yikes! situations? When they’re forced into one, can they survive it? And will their managers accept that, sometimes, Nelson Cruz with the bases loaded in a tie game is just going to happen, and it’s not worth forcing Oliver Perez into retirement to avoid it.