Romo suffered the broken finger last Sunday during overtime of what turned out to be a loss to Arizona and the Cowboys said at the time the quarterback might be out of action for a month.
Romo, who wore a split on his right hand during practice, said he thought he was healthy enough to play this week and Coach Wade Phillips appeared to agree.
"He threw the ball pretty well," Phillips said. "A quarterback just throwing the football isn't all they do. But I'm not going to count him out as far as the game is concerned."
Although Romo practiced Thursday, backup Brad Johnson took most of the snaps with the first-team offense. Johnson, starting quarterback for the Super Bowl winning Tampa Bay Buccaneers six years ago, has not started an NFL game since December, 2006.
Phillips said a decision involving Romo would probably not be made until game time on Sunday.