It was the perfect calm and perhaps the primary reason the Eagles exceeded expectations in Chip Kelly's first season as the head coach. The same five offensive linemen started all 17 games, including the playoff loss to the New Orleans Saints. That's not as rare as a baseball team going through a season with only five starting pitchers, but Eagles offensive line coach Jeff Stoutland has been around long enough to know it's not the norm either.

"I would say 2013 was an unusual year," Stoutland said Monday morning as the Eagles prepared for their mandatory minicamp that begins Tuesday. "I don't think we had any injuries that year. Maybe there was a nick where a guy missed a few plays, but I don't remember having a player out of that group that missed any extended time. Since that time, every year has been something."

Last year was a ton of somethings. It was, in fact, the perfect storm and perhaps the biggest reason the Eagles failed to make the playoffs in Doug Pederson's first season as the head coach.

Eight different linemen started games. Only the Jasons - left tackle Peters and center Kelce - started all 16 games. Four different players started at right tackle and Matt Tobin was used a few times in relief at the position. One rookie - Halapoulivaati Vaitai - started six games at right tackle in place of the suspended Lane Johnson before suffering a season-ending knee injury. Another rookie - Isaac Seumalo - started two games at right guard, one game at left guard and one game at right tackle.

Veterans Allen Barbre and Stefen Wisniewski combined to start 15 of 16 games at left guard with Barbre also accounting for three of the starts at right tackle.

When you combine all the upheaval up front with a rookie starting quarterback who was saddled with a sad-sack receiving corps, it is amazing to think the Eagles won seven times last season.

The great news for the Eagles out of all this: They should be much better prepared to handle turmoil along the offensive line in 2017 and it is reasonable to think that their luck along the line should fall somewhere between the good fortune of 2013 and the misfortune of 2016.

"I feel the majority of the [offensive line] players that are here right now are ready to play," Stoutland said. "They could go play right now and win football games."

That's because most of them have played. With the free-agent addition of guard Chance Warmack, the Eagles have eight linemen who have gone through at least one season as a starter. Talk to Stoutland about Warmack and his eyes light up. The two were together at Alabama before Warmack was taken 10th overall by Tennessee in the 2013 draft.

"Chance and I had a lot of success together in the past," Stoutland said. "I know Chance like the back of my hand. I'm excited about getting back together with him and getting him to the level he played at when we were together before. I guess I just know the buttons to push in coaching him. I know the technique he needs to perfect to be better."

Stoutland, however, is equally as excited about the upcoming second seasons for Vaitai and Seumalo as well as the 14th season for Jason Peters, who will join his teammates for the first time Tuesday after skipping the OTA portion of the offseason workouts.

"Night and day, apples and oranges," Stoutland said when asked to compare Vaitai's level of play now to a year ago. "Just his understanding of the [tackle] position, his balance and body control, the way he uses his hands. This is a lot faster game than college and I think he was able to understand that and have a little more sense of urgency on the set lines."

Seumalo, meanwhile, impressed Stoutland with his ability to move around to three different positions.

"He played a lot of football in his first year," Stoutland said. "I think just that experience and understanding each of those positions and the angles you have to take was impressive. He's a very intelligent player. I love coaching players of his magnitude. They have talent, they're smart. Really all you do is coach him one time on something and he pretty much has it."

With so much experience up front, the Eagles are prepared for the worst, but still hoping for the best.