The Diamondbacks maintain that Prieto simply made a mistake when he wore his smartwatch during the game.

MLB isn't revealing the size of the fines, which will be donated to Hurricane Maria relief in Puerto Rico. In practice, though, the penalty is more about the message it sends. The league wants to make it patently clear that the Apple Watch and other connected wearables don't belong on the field, even if their owners are only interested in checking the time.