"That's something we need to talk about internally," an annoyed Mattingly said. "We only have four guys [on the bench]."
The Dodgers are playing with a four-man bench in order to keep a 13-man pitching staff after short starts wore down the bullpen.
The ejection was the first of the season for the Dodgers and the seventh of Kemp's career.
Ken Gurnick is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.