Wilyer Abreu has been one of Boston’s best all-around hitters for much of the season and lately has consistently slotted into the top of the lineup. Yet whenever a lefty is on the mound, the rookie outfielder almost always sits.

That’s no accident, and Red Sox manager Alex Cora explained his philosophy with developing young left-handed bats at length prior to Thursday’s game.

“Throughout my career as a manager, if you look at my track record, all these lefties, they platoon because I know how tough it is,” Cora said. “Most of his at bats are going to be against righties, we’ll pinch hit for him against lefties and with time I bet he’ll start hitting lefties.

“We did it with (Triston) Casas and it worked out, we did it with (Rafael Devers), people forget we pinch hit for Raffy in Game 1 of the World Series, and it worked out,” he continued. “That’s how I manage it, that’s how I like it and we’re going to stay with the program.”

Entering Thursday night Abreu had taken 110 at bats against righties versus just 20 against lefties. The results have been stark, with the 24-year-old batting .305 with a .938 OPS against righties while posting just a .167 average and .472 OPS in his limited opportunities against lefties.

But if Casas’ experience is any indicator, Abreu should start getting more opportunities before long. Last season Casas got 405 at bats against righties and only 97 against lefties, but this year prior to his injury he was playing every day, and he was becoming even more productive against lefties (.286, .994) than he was against righties (.228, .807).

Like Casas, Abreu is renowned for his control of the strike zone, which helped him overcome a slow start to the season while allowing him to remain productive even during the occasional slump.

“At this level, the good ones, the elite ones, when they’re not hitting they’re taking their walks. And you see the numbers, I’ll go to MLB.com and the last seven games (he’ll be) hitting .210 but his on-base percentage is .380,” Cora said. “That tells you he’s still swinging at the right ones, he’s just running into some bad luck or swinging and missing at certain pitches.

“If he were a swinger then you go through the growing pains, chasing pitches, they’re going to attack you out of the zone and you’re going to swing at that and that’s why you struggle,” Cora said. “But you talk about how hard it is, the adjustment, it seems like it’s easier because of what he can do in the batter’s box.”

Abreu certainly hasn’t been slumping lately. Entering Thursday he was actually batting .333 with a .375 OBP and a monstrous 1.242 OPS over the past week, and on Wednesday night he hit his fourth home run of the season. Overall his 1.7 wins above replacement ranks third on the team behind Jarren Duran (2.3) and Kutter Crawford (2.1), so at this rate it’ll likely be just a matter of time before he fully earns Cora’s trust and becomes an everyday fixture.

But for now, Cora’s happy to let the rookie settle in so Rob Refsnyder and Tyler O’Neill can beat up on the lefties instead.

Extra innings

Right-hander Isaiah Campbell (right shoulder impingement) threw one inning of live batting practice Thursday. Cora said if he’s feeling good in the coming days he could potentially begin a rehab assignment. … Cora also said Garrett Whitlock (left oblique strain) is feeling good after his rehab start Wednesday and a decision on his return timetable will be made in the coming days.