Simmons was placed on the 10-day injured list with a right shoulder strain Thursday, retroactive to July 11, Taylor McGregor of Marquee Sports Network reports.
Simmons started in just one of the last five games, and he's apparently been dealing with a shoulder issue that will keep him off the field for the team's upcoming four-game series against the Mets. Since the move was backdated to Monday, the 32-year-old will be eligible to return as early as July 22, when the Cubs resume play following the All-Star break. However, it's not yet clear how much time the middle infielder is expected to miss.