Jay Cutler and Carson Wentz switched roles on Monday night. While Wentz looked poised, Cutler looked shaky, losing a fumble and throwing an interception before leaving the loss with a hand injury.
Cutler, who wore a protective cast on his right hand at the postgame news conference, said he would undergo further tests Tuesday.
"I'm concerned," he said. "As a quarterback, you need your right thumb."
Cutler said he aggravated the thumb injury earlier in the game and "couldn't really grip the ball," which he said contributed to him to throwing an interception to Eagles linebacker Nigel Bradham with 36 seconds left in the third quarter.
That turned out to be his last play of the game, and he was replaced by Brian Hoyer.
"I couldn't get as much on it as I wanted to, to put it over the top of that backer," Cutler said of the interception. "It was unfortunate, hurt the team. I knew I was putting the team, especially the offense, in jeopardy at that point. … I knew my day was done."
Cutler, 33, completed 12 of 17 pass attempts for 157 yards and one interception. He also lost a fumble. An 11-year veteran, he has missed 15 games because of injuries since 2010.
Cutler broke his right thumb in a November 2011 game against the San Diego Chargers while trying to make a tackle following an interception. The injury caused him to miss the rest of the season.
The Bears were 7-3 after beating the Chargers but lost their next five and didn't make the playoffs.