James underwent an MRI at the Cleveland Clinic in Toronto, which confirmed the sprain. The team said he will be a game-time decision for Friday night's game in Toronto against the Raptors.
James hurt his finger in the second quarter of Wednesday's 109-74 loss to Detroit. He did not respond to a few questions as he walked to the team bus after the game carrying a pizza.
He returned to Cleveland's bench late in the third quarter, sporting a suit and turtleneck, with tape wrapped around his index and middle fingers on his non-shooting hand. Late in the half, ice was packed and wrapped briefly over his left hand.
He appeared to be injured with 4:41 left in the first half, when Detroit center Nazr Mohammed fouled him. James made both free throws and stayed in the game.
"I didn't hit him that hard, but it's easy to sprain a finger," Mohammed said. "I'm sure he'll be OK."
James, who leads the NBA in scoring with 31.7 points per game and is
averaging 8.5 assists and eight rebounds, had 15 points and three assists in the first half, accounting for more than one-third of the Cavs' points, in a rematch of the Eastern Conference finals.
He had been sensational recently, including Tuesday night in an overtime win over Boston, and entered the game averaging 31.7 points, 8.5 assists and eight rebounds a game this season.
The Cavs did not practice on Thursday.
While the team says James is day to day, the Cavaliers likely
will be overly cautious with the injury so he doesn't make it
James was playing his first game at the Palace since Game 5 of
last season's Eastern finals when he scored 48 points,
including Cleveland's final 25, as the Cavaliers beat the Pistons.
Information from The Associated Press is included in this report