Indianapolis Colts running back Joseph Addai left in the first quarter of Sunday's game against the Baltimore Ravens with a hamstring injury.
Addai limped off the field after a two-yard gain on the first play of the Colts' second series.
Addai entered the game as the Colts' leader with 213 yards rushing and four touchdowns.
Third-stringer Mike Hart also left in the second quarter with a right knee injury.
That left Dominic Rhodes as the only remaining back on the active roster, and he ran 25 times for 73 yards.
In Denver, Jacksonville Jaguars running back Fred Taylor returned midway through the third quarter after sitting out most of the first half following a blow to the head against the Broncos.
Taylor had one carry for no yards on the Jaguars' first drive of the game. He also caught a 10-yard pass, but turned the ball over after he was hit by Broncos linebacker Nate Webster. Jacksonville cornerback Omare Lowe later left with a hamstring injury.
The Broncos were without three of their offensive playmakers in rookie receiver Eddie Royal (ankle), tight end Tony Scheffler (groin) and tailback Selvin Young (groin), and they lost slot receiver Brandon Stokley to a concussion shortly after his 11-yard touchdown catch that capped Denver's opening drive.
The Bengals are one of two winless teams in the NFL and there's more bad news for Cincinnati. Quarterback Carson Palmer will have his ailing elbow examined by a New York Mets team doctor.
Palmer said after the Bengals lost 26-14 to the Jets that he would remain in New York to be examined by Dr. David Altchek. Palmer was designated as the third quarterback for the game behind Ryan Fitzpatrick and Palmer's brother Jordan, the second game this season he has missed with the elbow injury.
"I'll play whenever they give me clearance," said Palmer, who injured his elbow against the New York Giants three weeks ago, missed a game against the Browns, then played against Dallas last week.
He said he had been told that his injury is the kind common to baseball pitchers, one reason he decided to consult Altchek.
The Bengals (0-6) and Detroit (0-5) are the NFL's only remaining winless teams. Houston and St. Louis both got their first victories on Sunday.
In other AFC North news, Cleveland Browns tight end Kellen Winslow has been released from a hospital after a four-day stay for tests and evaluation related to an undisclosed illness.
The Browns downgraded the Pro Bowler from questionable to doubtful for tonight's game against the New York Giants, meaning there's about a 25 percent chance he'll play.
If Winslow is out, Steve Heiden most likely would start and backup Darnell Dinkins would get more playing time.
Winslow was admitted to the Cleveland Clinic on Thursday after feeling ill for several days.
The Philadelphia Eagles scratched receiver Kevin Curtis from their starting lineup against the 49ers, delaying his season debut for another week.
Fellow starting receiver Reggie Brown, All-Pro running back Brian Westbrook and guard Shawn Andrews also were scratched due to injuries.