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 his throwing an interception to Eagles linebacker Nigel Bradham with 36 seconds left in the third quarter.
That turned out to be his final 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."
Before Cutler left the field, television cameras caught him in a brief confrontation with injured outside linebacker Pernell McPhee on the sideline. McPhee, one of the Bears' leaders on defense, is on the physically unable to perform list with a knee injury.
"I'm fine with that," Cutler said. "He's a passionate guy. Everyone has a lot invested into this, and he does as well. No one likes to lose. No one likes to lose in that fashion. He's upset. I'm upset."
Cutler, 33, completed 12 of 17 pass attempts for 157 yards and one interception. He also lost a fumble.
An 11-year veteran, Cutler has missed 15 games because of injuries since 2010.
He 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 games and didn't make the playoffs.