Kevin Long helped Kyle Schwarber against lefties. He’s trying to do the same with Brandon Marsh.

Kevin Long has had an ongoing conversation over the last few months with Phillies center fielder Brandon Marsh. It reminds Long, the Phillies hitting coach, of a conversation he used to have with a another hitter a few years ago.

Kyle Schwarber overlapped with Long for the first half of his 2021 season when they were both with the Washington Nationals. Like Marsh, Schwarber is a lefty who struggled to hit against left-handed pitching. Because of that, he rarely made starts against left-handed pitchers, and was frequently pitch-hit for when a lefty reliever entered a game.

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It became more of a mental problem for Schwarber than a physical one. For years, he would stare at the opposing team’s bullpen from the dugout, trying to catch a glimpse of who was warming up. If it was a lefty, he knew he wouldn’t get another at-bat. This kind of exercise didn’t exactly inspire confidence.

So, he got to work with his hitting coach. Schwarber faced every left-handed pitcher the Nationals had in their system that spring. The repetition helped. With each at-bat, his eyes, his body, and his mind became more accustomed to seeing the ball come out of a left-handed arm slot. By opening day, he started to feel more comfortable hitting against lefties, and his stats reflected that. Schwarber hit .189/.295/.302 against lefties in 2020. He improved to .268/.389/.398 against them in 2021.

Schwarber didn’t hit well for average against lefties in 2022, batting .193, but he did show improvements in other areas. His walk rate of 13.1% against lefties ranked fifth best among left-handed hitters in baseball (with at least 100 plate appearances) and he ranked seventh among left-handed hitters in hard contact against lefties, hitting a career-high 10 home runs and posting a hard-hit percentage of 38.3%.

Long has already started to take the same approach with Marsh, who has an opportunity in front of him. When the Phillies acquired the 25-year-old center fielder at the trade deadline in August, he was splitting time at the position with Matt Vierling. The Phillies traded Vierling to the Tigers in late January, which seemed to be a vote of confidence in Marsh’s ability to close the gap between his right-handed and left-handed splits.

It won’t be an easy gap to close. Marsh hit .262 in 328 at-bats against righties and .188 in 96 at-bats against lefties last season, striking out at a rate of 41.9% against left-handers. But Long believes that repetition will help Marsh, the same way it helped Schwarber. So, in an attempt to expedite this process, Long and Marsh, who both live in Arizona, have been hitting almost every day.

Long, who is left-handed, throws to Marsh. He tries to show Marsh as many different angles and speeds as he can. Sometimes that means throwing sidearm, other times it means stepping across his body, and more times than not, it means mixing in a few sliders.

“He can run up the radar gun,” Marsh joked. “He’s a competitor. He does some crazy stuff out there.”

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Long’s hope is that the work they’re doing in the offseason will help Marsh feel comfortable enough to face most lefties over the course of the 2023 season. There will be exceptions to this. Marsh likely won’t face a lefty with a funky delivery, like a Chris Sale or a Clayton Kershaw. But Long thinks Marsh will be able to make starts against someone like the Rangers’ Martin Perez, whom the Phillies likely will see in their season-opening series in Texas.

Marsh’s main focus right now is to line his feet up with the pitcher’s release point. If the ball is coming from left-center field, he will face that way. If it’s coming from right-center, he will face that way.

“It’s just so he has an open path,” Long said. “He’s going to keep that direction throughout his swing. From there, it’s a matter of just everything else he does: let the ball travel, stay tight, stay compact. It’s just about giving yourself the best opportunity to keep your bat and your eyes on the baseball. It basically enables him to be freed up and make a move to the ball that’s easy and really much like it would be against a right-handed pitcher.

“Facing a lefty is a different feel. Everything’s moving pretty much away from you, whereas with a righty everything’s pretty much moving into you. Once he gets used to at-bats against lefties, different angles, different release points, different breaking balls, he’s going to get better. There’s no ifs, ands, or buts about it. It’s going to happen.”

Marsh described it as “tricking” his brain to fight through specific moves he wants to make to better see the ball. Many left-handed hitters have a tendency to close off when facing lefties. Marsh is now trying to keep his front foot a little more open.

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Shortly after the Vierling trade, Phillies president of baseball operations Dave Dombrowski described the Phillies as “hopeful” that Marsh would become their everyday center fielder. He said they believe that Marsh will learn to hit left-handed pitching.

Now, it’s up to Marsh to prove them right.