Boston Red Sox first baseman Steve Pearce let a pop up in foul territory drop behind him.  

The reason he let the ball drop was because he thought he was called off by a teammate.  It turned out it was an Orioles fan who called him off.

Lucky for him it never happened, because the game was later postponed due to heavy rain.  

Because the game failed to reach the 5th inning, as the tarp was rolled out in the 2nd, they will have to play the entire game at a later date and this play never happened.