The league upheld the decision after Hawkins appealed the suspension. Yankees manager Joe Girardi said he was disappointed that there was no reduction in the penalty.
"There's not a whole lot that we can do about it," he said. "You just move forward and you find a way to use your bullpen being one guy short."
Hawkins was ejected from the game in Baltimore, but said afterward that the throw was not intentional.
In April, Yankees reliever Kyle Farnsworth was suspended for throwing close to the head of Red Sox outfielder Manny Ramirez. He appealed the suspension, and it was reduced from three games to one.
Hawkins holds a 1-1 record and a 6.08 ERA in 22 appearances this season.
Samantha Newman is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.