Oops.

A Major League Baseball coach has been fined for illegally wearing his Apple Watch in a dugout during a playoff game.

An investigation cleared Arizona Diamondbacks coach Ariel Prieto of any cheating, but he and the team were fined undisclosed amounts Friday because he wore the smartwatch during the Dbacks’ National League wild card game Wednesday against the Colorado Rockies. 

The penalties come about a month after the Boston Red Sox were fined by the MLB for using a wrist-worn device to steal signs during games with arch-rival the New York Yankees, who filed a formal complaint. MLB Commissioner Rob Manfred has said that while there’s no rule against stealing signs, using electronic devices and certain wearables like a watch to do so is a violation. 

The MLB prohibits players and coaches from wearing certain electronic communication devices, such as Fitbits and smart watches, on the field during games. Other gadgets are allowed. Teams can use iPads containing statistics, scouting reports and video. And last season, the league OKed the use of the Motus Baseball Sleeve, which tracks throwing, and the Zephyr Bioharness, which monitors heart and breathing rates.

League officials said in a statement that they examined Prieto’s Apple Watch and found no evidence it was used for “any baseball-related communication” during the game. The fines will go toward Hurricane Maria relief in Puerto Rico, the league said. 

The Diamondbacks beat the Rockies 11-8 in the game, to advance to the divisional playoffs. It’s a safe bet Prieto won’t be wearing his watch when the Dbacks take on the LA Dodgers starting Saturday.