The Chicago Cubs have placed All-Star shortstop Dansby Swanson on the 10-day injured list with a left heel contusion.
Swanson had already been ruled out of Tuesday's All-Star Game because of the injury after being selected as a reserve for the second straight season.
He had left Wednesday's win over the Milwaukee Brewers because of the injury, and the IL move is retroactive to Thursday.
"It is unfortunate to get into this position," Swanson said before the Cubs continued a three-game series with the New York Yankees. "The biggest thing, just from a timing standpoint, I'm getting four days with the break. It was almost, in a way, like a good insurance policy not to lose some retroactive dates."
Swanson, who signed a seven-year, $177 million deal with the Cubs in the offseason, is batting .258 with 10 home runs and 36 RBIs in 83 games.
The Cubs called up Miles Mastrobuoni from Triple-A Iowa in a corresponding move. Mastrobuoni, 27, is hitting .145 with an RBI in 29 games for Chicago this season and has hit .305 in Iowa. He will play third base and hit ninth Saturday.
The Associated Press contributed to this report.