The Los Angeles Dodgers weren't allowed to send a position player to the mound to pitch in the ninth inning against the New York Mets on Saturday night after unknowingly violating a recent addition to the rulebook.

Dave Roberts intended to use utility player Zach McKinstry to record the final three outs of the 9-4 contest, but the Dodgers had already used six pitchers after starter Walker Buehler was pulled in the third inning.

Umpire C.B. Bucknor's explanation invoked a rule that Major League Baseball and the MLB Players Association had agreed upon ahead of the 2020 season that would bar position players from pitching in games with a deficit of five runs or fewer unless they were designated two-way players.