Sometimes it's OK to say something kind of mean, as long you're saying it to a friend.
Perhaps that's a rule former Diamondbacks catcher Jeff Mathis lives by. When he was behind the plate for the Rangers Tuesday, he wasn't afraid to slide in a few jabs at Zack Greinke when the pitcher came up to bat.
"He was making fun of my haircut," Greinke said. "And I told him part of the reason I cut it was so my helmet would stop falling off. But it still falls off. So it's awful."
The other part?