And Peters was 31.
Peters, who arrived from Buffalo in 2009, not only was named to his sixth Pro Bowl in seven seasons, he clearly was the team's most irreplaceable offensive player.
"I'd agree with that," center Jason Kelce said. "Jason's extremely important, because he physically is better than every opponent he plays on a week-to-week basis. Occasionally, he'll get beat on pass protection, but those instances are few and far between. Especially toward the end of the season last year: He was on fire.
"In the run game, he gets unbelievable movement. He comes downhill with great force. In pass protection, you can leave him one-on-one, you don't have to worry about him at all."
For anyone to consider any player more significant than McCoy is saying a lot. McCoy might be the most dangerous running back in the NFL: He is elusive, he has breakaway speed, and he is a fine receiver. He might be the best in Eagles history. He's on his way to a Hall of Fame career.
McCoy should expect Peters to be there to meet him.
"I tell people this all the time: I think Jason Peters is probably the best athlete I've ever seen play," Kelce said. "A lot of people are taken aback by that. To see a man that big be that athletic . . . We're not talking just speed and quickness. He's never off-balance, it seems. He always strikes somebody in a good position. It's kind of fun watching him play on film. I don't think there's a better tackle in the game, when you talk about overall ability."
Peters allowed only four sacks in 2013. No team ran better behind the left tackle position.
It was, said Peters, his most challenging season as a pro.
"The combination of both - the Achilles' injuries, and having a new offensive-line coach, and a new head coach, was the toughest," Peters said. "You've got to start all over again. I was doing both. Coming off an injury and having a new head coach."
Peters stressed having a new head coach for two reasons.
First, Kelly's uptempo offense demands that all players function at peak physical capacity. Peters, who hovered around 340 for much of his career, is now listed at 328 pounds. He adhered to Kelly's sleep and nutritional edicts, and he thrived.
Second, the Eagles largely were built around Peters.
He took home $10.75 million last season, which made him, by far, the highest-paid Eagle. He agreed to a 5-year extension in February that guaranteed him $15.75 million in the next two seasons.
Players who make that sort of cash tend to be more aware of their head coach than their position coach.
Players who make that sort of cash are cornerstones.
"I think so," Peters agreed. "You have a good left tackle, it makes the whole offensive line better. It makes the quarterback better. Foles had an unbelievable year last year, and you see what happened with him. I think it starts with the offensive line."
(Foles declined to talk about Peters' importance.)
If anything, Peters remains as hungry today as he ever was.
In 2004, Peters was an undrafted free agent whom Buffalo signed with a $5,000 bonus and a promise that he might make the team at his original position, tight end. He made it, learned the right tackle position by the end of 2005, moved to left tackle in the middle of 2006 and was in the Pro Bowl by 2007.
While coaching a herd of future NFL linemen at Alabama, Stoutland famously used Peters as the example.
Nevertheless, on Monday there was Peters at practice, concentrating on his moves at the line of scrimmage as intently as a ballet dancer on pointe.
"That's what I work on: my pass protection, all the time. Working on my feet and my hands," Peters said. "The run-blocking stuff will come. I work on that all the time. I'm just trying to refine my pass protection. As you know, it's a passing league. They get good pass-rushers every year out of the draft, and they're trying to beat you."
The work is a little easier this offseason. He is healthy, he has the same coaches, and the team is not in turmoil. He arrived with fanfare in 2009; played through the Donovan McNabb trade and Michael Vick/Kevin Kolb quarterback issues in 2010; endured the Dream Team nightmare of 2011; missed 2012; then found a bizarre new regime in place in 2013.
"He's a happy football player now," Stoutland observed Monday.
"Anytime you can be injury-free and not have new coaches, it flows a little bit smoother," Peters said.
Which portends for, at least, continued excellence. The Eagles cut Jackson to save money (and a little sanity), but they drafted two promising receivers last month, traded for free-agent scatback Darren Sproles and feature three potentially potent tight ends.
None of which matters if Peters isn't Peters.
McCoy and Jackson and Foles all showed that teams can scheme to stop them. Nothing stops Peters.
"Players know when they line up against me they have to give me their all," Peters said, "or they're not going to beat me."
Second-year rookie free agent Matt Tobin is listed behind Peters on the depth chart, but if Peters were lost for a significant amount of time, the Birds might switch second-year first-rounder Lane Johnson from right tackle to left, move right guard Todd Herremans back to right tackle and pop in one of their backup guards.
Still, there would be no greater dropoff at any position if Peters were hurt.
There just isn't anyone like him; no one who essentially is conceded a trip to Hawaii in June.
"If I can be a Pro Bowl player, it makes the team that much better," Peters said. "I just want to stay at that caliber of player."
If he doesn't, Shady and Chippah and Nick the Quick will be in for a long season.
On Twitter: @inkstainedretch