JASON PETERS is a five-time Pro Bowler. Might be the best left tackle in the game.
When you lose a player of Peters' caliber, hearts sink and hope takes a holiday.
But when he went down for the second time late in the first quarter Sunday with a done-for-the-day quad injury, neither quarterback Nick Foles nor the rest of the Eagles' offensive line rushed for the Prozac.
"When you see Jason go down," said left guard Evan Mathis, "you think, 'Ah, man,' because you don't like to see a teammate get hurt.
"But it's not like, 'Oh no, here comes his backup.' It's like, 'OK, Allen's here. It's no big deal. Everything's going to be OK."
Allen is backup offensive lineman Allen Barbre. He stepped in for Peters Sunday, just as he did for 17 plays against the Raiders the week before and nine plays against the Bucs last month, and the trains kept running on time and the Eagles' offense didn't miss a beat.
They racked up 400-plus yards for the eighth time in 10 games. For the sixth time in those 10 games, they scored at least 27 points. LeSean McCoy rushed for 155 yards. Foles threw three touchdowns and no interceptions.
Peters said he definitely will play in Sunday's important NFC East game against the Redskins. But he would say that - and mean that - even if they had just amputated both of his legs.
If he can't go, Barbre, 29, will make just his eighth career start in seven seasons and first since 2009.
"Al's a tremendous player," center Jason Kelce said. "I'm glad he's getting some opportunities to showcase that.
"When he comes in, you know you're getting a quality player and that your offense isn't going to miss a beat. That's what you look for in backups.
"You're not necessarily looking for a game-changer. You're looking for a guy who's going to come in and it's not going to affect your offense. To have a guy like that who can really fill in at any position on the offensive line, with maybe the exception of center, and not miss a beat, that's really valuable."
Barbre was impressive against the Packers. Played 52 snaps. Went up against Packers linebackers Clay Matthews and Mike Neal and Nick Perry and handled them all.
Granted, Matthews was playing one-handed, his right hand completely wrapped to protect a healing broken thumb. Nevertheless, Barbre didn't let the four-time Pro Bowler get anywhere near Foles.
He did a superb job of neutralizing Matthews on Foles' 55-yard touchdown pass to DeSean Jackson in the first quarter. Early in the third quarter, he blocked Neal and then slid over and picked up blitzing safety Morgan Burnett and wiped him out on Foles' 45-yard TD pass to Riley Cooper.
"[Matthews] couldn't do some of the things he could do when he had two hands," Barbre said. "But he's still a great player. Real shifty, real agile. You still have to be physical with him."
Said Mathis: "Usually it's hard to have a guy as good as Allen as your sixth man because usually a guy that talented is one of your starters. You couldn't ask for a better sixth man than him because he can play guard and tackle at a very high level."
Because Barbre can play those positions, the Eagles only need to activate seven offensive linemen on game day - their five starters, backup center Julian Vandervelde and Barbre - which allows them to dress an extra special-teams player.
"I just focus on two positions and try to be prepared," Barbre said. "I did some good things [against the Packers], but there's still some stuff I need to work on.
"I'm just relying on my technique. Just relying on what I go out and do, what I practice on, and let it take care of itself in the game."
Barbre, a fourth-round pick of the Packers in 2007, has been cut four times, most recently by Seattle last September after the league slapped him with a four-game suspension for testing positive for performance-enhancing drugs.
He played just five offensive snaps the last three seasons and spent most of last fall hunting deer.
The Eagles worked out the 6-4, 310-pounder shortly after the Seahawks released him, but didn't sign him. In mid-January, they called him and offered him a contract.
"He was a guy we had followed since he came out of Missouri Southern," general manager Howie Roseman said. "Over the last 3 years, you could see that he continued to improve in the preseason.
"A lot of the things he had in his body in terms of athleticism, length, size, strength, it was all kind of coming together. We stayed in touch [after last fall's workout] and when the opportunity arose to sign him as a future [free agent], we thought we had to get him. It was almost like a first free-agent signing."
Much like the 32-year-old Mathis, who spent the first 6 years of his career as a journeyman with three teams before developing into one of the league's top interior linemen after signing with the Eagles in 2011, Barbre appears to be another late bloomer.
"Offensive linemen often take time to develop," Roseman said. "That's one of the positions where it doesn't necessarily happen right away. You just look for guys who have enough tools in their body to be able to play the position, and sometimes it just clicks."
After Peters ruptured his Achilles' tendon in 2012, the Eagles signed the top free-agent tackle on the market, Demetress Bell. Gave him a 5-year, $35 million contract with just a 1-year, $3 million commitment.
Bell ended up being a bust. He started just five games and was benched in favor of King Dunlap, who wasn't much better. The Eagles waved bye-bye to both of them after the season.
Last year, injuries wreaked havoc with the Eagles' offensive line. Peters missed the entire season. Kelce missed 14 games with a torn ACL. Todd Herremans missed eight games with a broken foot.
So far this season, none of their starting five has missed a start. If that changes Sunday and Peters can't go or somebody else goes down, Chip Kelly can take comfort in the fact that he's got a very capable replacement option.
"His ability to be both a swing guard and tackle for us, and really our first guy off the bench, was a huge plus for us," Kelly said.
"Then, to watch him play [Sunday], I thought he did a really, really good job in his first extended playing time, was really solid in protection, kind of helped us get to the edge a lot when we were running to the left. I'm really happy with him."
After 6 years of being an NFL nomad, Barbre is just happy to be playing well and with a team that values him.
"Maybe bouncing around helped me focus and has helped me do some of the little things right," he said. "Maybe that helped me. Maybe it put me where I needed to be."
On Twitter: @Pdomo