US media reported that Marshall had a collapsed lung and would miss the rest of the season, a scenario all the more likely as Chicago were eliminated from playoff contention with the 41-28 defeat.
Marshall exited the contest after he took a knee to the back from safety Barry Church while making a 15-yard reception in the second quarter.
Marshall was quickly taken to hospital, later tweeting "Thanks for the prayers … I'm good."
"It’s scary any time that a guy goes down and is laying on the ground," Chicago coach Marc Trestman said after the game.
Marshall, a five-time Pro Bowl selection, had three catches for 61 yards prior to departing the contest.
For the season he has 61 receptions totaling 721 yards and is tied for the Bears lead with eight touchdown catches.
However, he has endured a spate of injuries, including nagging ankle trouble.