Simmons has announced his retirement from professional baseball, Jared Tims of Talkin' Halos reports.

Simmons was released by the Cubs on Sunday, Tim Stebbins of NBC Sports Chicago reports.

Simmons (shoulder) was activated off the injured list and designated for assignment Saturday, Tim Stebbins of NBC Sports Chicago reports.

Simmons (shoulder) will begin a rehab assignment at Triple-A Iowa on Thursday, Meghan Montemurro of the Chicago Tribune reports.

Simmons (shoulder) took live batting practice Monday, Meghan Montemurro of the Chicago Tribune reports.

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 isn't starting Saturday against the Red Sox.

Simmons is not in the lineup for Sunday's game against Atlanta.