Unfortunately, it didn't help his day at the plate, as he went 0-for-4 in the 11-3 win Sunday at Minute Maid Park in Houston.
Bregman began the game by popping out in the first inning. He walked in the second inning and came in to score on Yuli Gurriel's grand slam.
But when Bregman came up to bat in the fourth frame, he was missing something. The Astros infielder went into the clubhouse and shaved off his mustache.
He flew out to begin the fourth frame. Bregman grounded out in the sixth inning and struck out in his final at bat in the eighth inning.
"I just shaved it," Bregman told reporters. He also said he might have done something similar earlier in his career.
Fox Sports Kansas City broadcaster Joel Goldberg talked with Astros radio announcer Steve Sparks about the mustache move.
"He's superstitious and he's a little bit weird, just like me," Sparks told Goldberg.
Bregman's teammate Gerrit Cole brought some levity to the situation, saying the mustache had been designated for assignment.
"I did like the mustache, I thought it played," Cole said. "It was Jeff Kent-esque. It was on top of his lip when he stabbed that soft liner in the first inning, which got us out of a jam. Personally, I'm a fan of the 'stache, but I guess it's been sent down. It's been DFA'd. We'll wait until it comes back."
Bregman is now hitting .259 on the season with 11 home runs and 43 RBIs.