The shoes, a gift from Nike presented to Wilson at the All-Star Game, apparently violated the league's dress code. It was the first time Wilson has worn them in a regular-season game.
"They all have to have the majority of your team's color on the shoe you wear," Giants manager Bruce Bochy said Wednesday. "I was aware of it. It's going to be up to me to make sure these guys stay in uniform. I agree with it. We'll make sure his shoes are acceptable."
Wilson was already on top of it. He sat in front of his locker before Wednesday's game against the Marlins and used a black marking pen to color in a portion of his cleats.
"The magic doesn't come from the shoes," Wilson said.
Wilson, who leads the majors with 30 saves, wore the same shoes during the All-Star Game and then broke them out Monday while warming up in the bullpen. He didn't pitch in that game but came in to work the ninth inning Tuesday.
"In the All-Star Game anything goes, it's a little different there," Bochy said. "I'm not surprised he got fined with that."
Florida manager Edwin Rodriguez questioned umpires about the shoes before Wilson pitched Tuesday and was told they could do nothing about it.
"I went to the umpire and I was wondering about the shoes," Rodriguez said. "He thought the rule was meant more for the sleeves than to the shoes, and he said, 'There's nothing I can do regarding the shoes.' I was surprised that they fined him without warning him. When I heard that he got fined, I said, 'Well, at least give him a warning to be fair.'"