The Cubs have shut down outfielder Jason Heyward (concussion) and Keegan Thompson (right shoulder inflammation) for the final week of the season, manager David Ross said Tuesday.
They placed Thompson on the 10-day injured list and recalled Jason Adam from Triple-A Iowa.
Additionally, the club is weighing whether to shut down infielder Nico Hoerner (general soreness).
Heyward last played Sept. 11, exiting the game after taking a knee to the head while sliding into third base. The play caused a concussion.
The Cubs have been exercising caution with Heyward due to the seriousness of the injury. Ross said Heyward is still experiencing small symptoms but is improving.
"It's gotten better every single day," Ross said. "He's sleeping better, the headaches and the dizziness and the fatigue is all waning towards being non-existent."
Heyward saw concussion specialist Micky Collins in Pittsburgh on Tuesday, according to Ross, and received a plan of rehab.
"I think that will be really good for him and he should bounce back pretty fast," Ross said.
Thompson began feeling soreness in his shoulder after his start Sunday vs. the Cardinals. The Cubs are being cautious as the season winds down.
Thompson struggled in his first few starts upon joining the rotation in August before going on the IL earlier this month. He pitched well in his final outing Sunday, allowing one run and three hits in a three-inning start, striking out seven.
Thompson said Sunday he's been working through things mechanically and mentally, adding the outing gave him the confidence he can start in the big leagues heading into the offseason.
"I thought there was a lot of power in there and for him to go out and prove to himself knowing where he was," Ross said. "Listening to some of the things he was going through mentally was very eye-opening.
"I thought it was real good stuff he showed in his last start," Ross added. "To get him back to throwing the baseball the way we believe he can and going into the offseason with that conference is huge for us and him."
Hoerner has had three stints on the injured list this season due to forearm, hamstring and oblique injuries. He was doing better Tuesday but still has some soreness in those areas, Ross said.
The Cubs are evaluating the best course of action with only five games remaining after Tuesday.
"Just see what he's able to do today and assess after that," Ross said.
Contributing from Pittsburgh: Gordon Wittenmyer