In 2013, the Eagles' first-team quintet of Jason Peters, Evan Mathis, Jason Kelce, Todd Herremans and Lane Johnson started all 16 games together, accounting for 98.3 percent of the snaps taken along the offensive line. Whether that continuity can be attributed to a specific training regimen, sports science or simply luck, it remains an unlikely best-case scenario. The job of general manager Howie Roseman and the rest of the team's personnel staff is to prepare for the worst-case scenario. And you need look no further than 2012, when 10 different players played for a beleaguered offensive line, to understand the importance of depth up front, especially for a team that utilizes its offensive line as the Eagles do.

So how does the Eagles' depth along the offensive line look with the NFL Draft in the rearview? Despite internal expectations that the team might add an offensive lineman in the draft, one never stood atop the team's draft board when the Eagles were on the clock. But all four backup offensive linemen who were on the Eagles roster last season return, along with several other promising players.

"I think that you can never have enough offensive linemen, and we'll always be on the lookout for those guys," said Roseman following the draft, jokingly adding that the absence of an offensive lineman from the draft class was a "dagger to the heart." "It's always going to be a priority for us. But we have this commitment – we're not going to reach.

"We need some of those young guys to step up, and they showed some promise, but when you go from year one to year two, I think that sometimes we've seen this league with offensive linemen that you think they have a lot of promise in year one, and then they come back year two and they need to take the next jump. Especially what happened here (not drafting any offensive linemen), we need those guys to take a jump."

So who will compete throughout the spring and summer to make the roster? Here's a rundown of the competitors, broken up into three groups:

Returning:

Beyond the starting five, four other offensive linemen spent the entirety of the 2013 season on the active roster: Allen Barbre, Julian Vandervelde, Dennis Kelly and Matt Tobin. Barbre, 29, is the veteran of the group and was the first man off the bench last year. For the other three, and second-year player Michael Bamiro, who spent the season on the practice squad, there remains much unknown. Kelly impressed in his rookie season of 2012, but has yet to show his stuff in the new offensive system. Vandervelde, the former fifth-round pick, has yet to receive much playing time, though his athleticism and intelligence should suit the system well. Tobin, meanwhile, forced his way onto the roster as an undrafted rookie thanks to a strong Training Camp.

"We had a chance every Sunday to see them work out before the game and see them in practice," Roseman said in January about the returning backup offensive linemen. "The big thing for offensive linemen is getting experience, so that'll be one of the things you're excited to see in Training Camp and the preseason games, those young offensive linemen getting reps and getting an opportunity to play a little more because it's hard to evaluate them and see how much better they're getting. But we have a heck of an offensive line coach (Jeff Stoutland) who works them out every week and I think you saw in one-on-ones during the season that they were getting better."

New Veterans:

This is the group from which Barbre emerged last season, after he was signed following the 2012 season and considered an afterthought by some. The Eagles added two veteran offensive linemen this offseason to compete come Training Camp – former Texan Andrew Gardner and former Charger David Molk. Gardner, 6-foot-6, 308 pounds, played in eight games over four seasons with the Dolphins (who drafted him in the sixth round) and Texans from 2009-2013. While Gardner will compete as a tackle, Molk will join the competition along the interior line. A seventh-round pick of the Chargers in 2012, Molk was a standout center at Michigan, where he once earned Big Ten Offensive Lineman of the year honors. He played in 12 games for the Chargers in 2012.

The other variable for this group is players who are not currently on the roster. For instance, 32-year-old veteran Daryn Colledge, who has started 124 games over eight seasons with the Packers and Cardinals, is reportedly visiting the Eagles this week. Whether Colledge joins the team or not, there is still a large group of veteran offensive linemen available on the street, if the team chooses to go down that road.

Rookie Free Agents:

Head coach Chip Kelly proved that he's open to undrafted offensive linemen making the opening week roster when Tobin accomplished the feat last season. Four such players will have that opportunity this year, after they signed with the Eagles following the draft. Karim Barton, 6-foot-2, 313, and Josh Andrews, 6-foot-2, 311, will compete at guard. Former Texas standout Donald Hawkins could be a player to watch, as he transitions to guard after playing mostly tackle in college.

NFL.com lists Hawkins' strengths as such:

"Can wall off, shuffle and sustain. Works angles in the run game and can gain positioning and lock out. Blue-collar worker with a serious, business-like approach. The game is important to him."

Like Hawkins, former USC tackle Kevin Graf plied his trade in front of Eagles scouts at the East-West Shrine Game, and probably comes to Philadelphia with the highest pedigree of the undrafted offensive linemen. Graf, 6-foot-6, 309, started 38 games at right tackle over three seasons with the Trojans.

NFL.com's pre-draft scouting report on Graf says he "gets out of his stance with urgency and plays hard. Provides enough protection for quick passing game. Mobile enough to step to the second level. Three-year starter at top program. Showed improvement as a senior. Outstanding 10-yard split (1.76 seconds) and 40-time (5.03 seconds) at his pro day."

With four or five spots on the roster likely up for grabs, the aforementioned 11 players will compete in trial by hand-combat over the next few months. In the battle for roster spots, summer is coming.

For more on the offensive line, check out the Position Preview.

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