Coach Mike Smith said Monday that Ryan will miss at least one game with a turf toe injury. Chris Redman, who took over for Ryan in Sunday's 20-17 win over Tampa Bay, will start against the Eagles.
Before the win over the Buccaneers, Redman had not attempted a pass since his last start in the final game of the 2007 season. Redman completed 23 of 41 passes for 243 yards with two touchdowns, including a 5-yard scoring pass to Roddy White with 23 seconds remaining, and no interceptions against Tampa Bay.
"It was good to get back out there and get back into the game and get a feel for it," Redman said Monday.
Ryan did not return after he injured his right big toe on the first series against the Buccaneers. Smith would not speculate on Ryan's status beyond this week.
"During the week he's going to work with our medical staff diligently to get back as quick as he can," Smith said.
The Falcons (6-5) lost three more starters on offense against Tampa Bay.
Running back Michael Turner aggravated his right ankle sprain in his return after missing one game. The team also lost offensive linemen Harvey Dahl (right ankle and Achilles tendon) and Sam Baker (left elbow).
Smith said Turner has not been ruled out of this week's game.
Smith added he plans to carry only two quarterbacks on the roster against the Eagles. Rookie John Parker Wilson, who has never been on the active roster for a game, will be Redman's backup.
The Falcons released quarterback D.J. Shockley earlier this season.
Ryan has passed for 2,291 yards with 16 touchdowns and 12 interceptions. He has completed 59.4 percent of his passes, a slight dropoff from his 61.1 percentage last year when he won Offensive Rookie of the Year honors.
Redman, Joey Harrington and Byron Leftwich were Atlanta's starting quarterbacks in 2007. The team struggled to a 4-12 finish following the NFL suspension of former Falcons star Michael Vick, who will return to Atlanta this week as Philadelphia's backup.
Redman passed for four touchdowns with no interceptions in the Falcons' 44-41 win over Seattle to end the 2007 season.
"Chris has got a lot of confidence in his ability and when he has had an opportunity to play in this league he has played effectively," Smith said. "I don't anticipate there is going to be a significant dropoff in the effectiveness of our offense."
Smith said Redman should benefit from his first significant playing time in two years.
"That's just part of being a backup, when you don't have that many practice snaps you just have to take mental reps," Redman said. "That's definitely different than getting out there and doing it yourself, and I could tell during the game just timing was a little off between me and Roddy and a couple of the guys. But everybody hung tough with me and we pulled through."
It will be the first game Ryan has not started in his two-year career. He made every start last season when he led the Falcons to an 11-5 record and a playoff berth.
Ryan had a walking boot on his injured foot and wore a black warmup suit as he watched Redman rally the Falcons past Tampa Bay in the final minute Sunday.
Redman said the Falcons' ability to overcome the four injuries should provide a confidence boost.
"There was no panic at all," he said.
"I think it does show the depth we have and I think that's something you need if you're going to be a playoff contending team."
Before Smith announced Ryan will not play, center Todd McClure said the team would have confidence in Redman as the starter.
"You'd like to have your starters, but if Redman is the guy, we have a ton of confidence in Redman," McClure said. "One thing that will be key and is key every week is getting our running game going and taking pressure off of him."
Turner was held to 33 yards rushing on 12 carries before he hurt his ankle again. Backup running back Jerious Norwood returned after missing five games with a hip injury and had six carries for 22 yards.