SAN FRANCISCO -- Philadelphia quarterback Koy Detmer, playing in place of injured Donovan McNabb, dislocated his left elbow and was carted off the field late in the third quarter of the Eagles' 38-17 victory over San Francisco on Monday night.

	Detmer

Detmer landed hard on his bent left arm after being tackled around the knees by Chike Okeafor following a 24-yard completion to Jeff Thomason with 3:32 left in the third.

''I feel OK,'' Detmer said. ''Obviously I'm disappointed for the injury, but right now I haven't got any time frame. I felt great. What a night. The conditions couldn't have been any better and the ball felt good.''

After the game, Eagles coach Andy Reid said that Detmer's status for future games has not yet been determined. Detmer will undergo a bettery of tests on Tuesday on the elbow when the team returns to Philadelphia, including an MRI exam.

Detmer kicked his legs in pain and was carted off about five minutes later. Just before he left the field, all of his Philadelphia teammates and the San Francisco defense charged over to him to wish him well.

''That was an awesome display of sportsmanship,'' 49ers coach Steve Mariucci said.

Detmer returned to the sideline in the fourth quarter, wearing an Eagles windbreaker. He will undergo tests Tuesday in Philadelphia.

Detmer was playing magnificently in his first start in three years. He threw for two touchdowns and ran for a 1-yard score.

Detmer, a career backup, did not appear to be as seriously hurt as some quarterbacks who have taken big hits in recent weeks.

''You have to be concerned,'' San Francisco cornerback Ahmed Plummer said. ''He has a family also. He's another man, just like I'm another man. I'll be praying for him.''

Pittsburgh Steelers quarterback Tommy Maddox was in uniform but didn't play Sunday against Cincinnati. A week before, he injured his spinal cord in a scary collision while playing Tennessee.

Maddox was hurt on the final play of the third quarter of the Steelers' 31-23 loss against the Titans and spent a night in the hospital with a concussion.

Detmer completed 18 of 26 passes for 227 yards and two touchdowns before leaving the game. He was replaced by third-stringer A.J. Feeley, a second-year pro who had not thrown a pass all season.

Feeley will get the start on Sunday aganist the Rams as well, the Eagles announced on Tuesday.

McNabb broke his right ankle on the third play of a 38-14 victory over Arizona two Sundays ago, but stayed in for most of the game. He might miss the rest of the season, including the playoffs.

Detmer, a seventh-round pick by the Eagles out of Colorado in 1997, was 1-4 as a starter in 1998 for a team that finished 3-13. He won his only start in 1999, when the Eagles went 5-11. Coming into Monday's game, Detmer had completed 113 of 227 passes (49.7 percent) for 1,240 yards, eight TDs and nine interceptions in six seasons.