White Sox reliever Mike Vasil impressing with dual personalities as clubhouse leader and on-field Batman

The Batman mask hanging in White Sox reliever Mike Vasil’s locker is hard to miss.

It would be easy to chalk it up as a fun trinket for a fan of the character, and that’s kind of what it is.

But it’s also part of the key to Vasil’s success in his rookie season on the South Side, an inspiration for a dual identity that has made him a key cog of this rebuilding team, on the field and off.

“For me, it’s something that motivates me a little,” Vasil told the Sun-Times on Saturday. “At the same time, I really don’t know who that guy is sometimes on the mound. It really is a different person.

“I kind of just came up with the idea from the fact that I really like the [Batman] movies, and also I’ve always toyed with, ‘If you’re going to be that guy on the mound, you’ve got to be that guy off the field.’ Then I realized that doesn’t have to be the case.

“I figured, who’s better at that than Batman?”

Yes, Vasil has a secret identity.

Off the field, he’s a regular Bruce Wayne — though perhaps a little more fun and down-to-earth than the fictional billionaire — who’s quickly emerging as a team leader.

On the field, though, his competitive side comes out, and he has used it to come up big in the first half, performing in a variety of relief roles and heading toward the All-Star break with a 2.47 ERA.

Put him on the mound, and he’s Batman.

Look at the heroics he delivered in the Sox’ extra-inning win Friday. Pitching in heavy rain, conditions fit for a climactic superhero battle, he threw three scoreless innings, stranding the bases loaded in the 10th inning and leaving two men on base in the 11th.

“I’m a guy who just loves to pitch to win games,” Vasil said after the game. “Any role I can help the team win, to be able to go out there and have the confidence that I’m in there for a reason and to be able to go out and win the game or be part of it is awesome. I live for that.”

As for the emotion he showed?

“If you have any insight into what the Batman guy is like,” he said, “that was probably him.”

But this isn’t a case of a hero’s alter ego taking a mild-mannered back seat.

All sides of Vasil’s personality — the on-field guy and the off-field guy — are making a difference for a Sox team looking to build a culture as it rebuilds for the future.

“[He’s made a] big impact behind the scenes,” manager Will Venable said Saturday. “He’s a big personality. He’s a guy that’s vocal. He’s a vocal leader in the group. He’s a guy that keeps the guys loose.

“He’s obviously very intense and competitive and kind of leads the charge in that way. He’s meant a lot. And when you have that in the clubhouse and then you go out on the field and you do what he does, you start to believe in the whole package.

“He plays up to the role out there of being a guy who gets the job done. He likes that.”

A late-spring waiver claim, Vasil was the second player chosen (by the Phillies) in last winter’s Rule 5 Draft on the Sox’ roster, along with All-Star right-hander Shane Smith. A starter throughout his minor-league career, his transition to a relief role with the Sox has been nearly flawless.

Had Smith not been the choice to represent the Sox in the All-Star Game on Tuesday, Vasil, who has thrived in bulk-innings situations as well as high-leverage ones, would have warranted consideration.

“I started my whole minor-league career, but being able to serve the team in multiple ways is a lot of fun,” Vasil said. “I’ve always been the guy that sometimes when I’m on the bench as a starter in the past, you want to be in the game in those situations. When you get that opportunity, it’s really cool.

“Just be able to do whatever role, whatever capacity to help the team win, that’s what’s most important for me.”

The next time the Sox need to call on Vasil for that kind of thing, forget the bullpen phone.

Just shine the Bat signal.