Heading into the season, MLB made interference calls around the bags a point of emphasis for umpires. Basically, the league wanted to legislate out of the game fielders blocking the bag with their legs. Still, it’s a seldom-called rule, and the selective enforcement understandably doesn’t sit well with most managers.

Alex Cora was as angry as he has ever been at the umpiring crew Sunday afternoon. He explained after the game what set him off.

Watch: Red Sox manager Alex Cora was ejected after arguing an interference call Sunday. Read more on Boston.com.