Martin claimed Diaz wouldn't let him throw new baseballs back to his pitchers after fouls during Wednesday's game against the Los Angeles Angels.
Martin said the "punishment" occurred after he exchanged words with Diaz early in the game.
"He said that it was a privilege that I had to earn, for me to throw the ball back," Martin said. "That's never happened to me before. I even told him, because there's guys on base, I like to keep my arm loose. Nope. 'I'm not letting you throw the ball back.' That's pretty strange, to me. That's a good story, huh?"
Diaz was unavailable to speak with reporters, because Martin spoke to them nearly an hour after the game.