Tillman left Sunday's game against Minnesota with an apparent ankle injury after Vikings tight end Rhett Ellison appeared to step on his foot during the second quarter. He came back onto the field after getting treatment for the injury but then left the game again.
The Bears beat the Vikings 28-10.
Citing a source, the Chicago Tribune reported Tuesday Tillman may be able to play this week against the Seattle Seahawks.
If he is unable to play, the Bears will go with Kelvin Hayden at cornerback, the Tribune said.
Tillman was placed on injured reserve in 2009 due to a bruised lung and fractured ribs, and was held out of the final game of the season against Detroit. He has played in every game for the Bears since the beginning of the 2010 season.