Yankees manager Joe Girardi was also fined for his vehement protest to umpire Brian O'Nora. Girardi was ejected, Dempster was not.
Dempster hit Rodriguez with a fastball on a 3-0 count in the second inning of the nationally televised game.
Dempster denied it was intentional. In its news release announcing the discipline, MLB explained the move was for "intentionally throwing at and hitting Alex Rodriguez."
"I was just trying to pitch inside," said Dempster, who threw behind Rodriguez with his first pitch.
Rodriguez later hit a solo home run off Dempster in the sixth inning, and had three hits and scored twice.
"Whether you like me or hate, that was wrong. That was unprofessional and silly. It was kind of a silly way to get someone hurt on your team as well," Rodriguez said.
Dempster's suspension began Tuesday. He said he would not appeal.
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