Dennis Kelly could be vital to the success of the Eagles offensive line

In 2012, the Eagles offensive line experienced an onslaught of injuries that caused major problems for the entire team. The relentlessly changing carousel of offensive linemen left quarterbacks consistently under pressure and running backs fighting to find holes. Left guard, Evan Mathis, was the only offensive lineman complete the entire season, despite being injured and requiring offseason surgery.

Although the failures of the offensive line were clearly based on a lack of depth, just a few months later, the unit is now in a position to be among the dominant groups in the NFL. All-Pro left tackle, Jason Peters, has returned after missing all of last season due to a twice-torn Achilles tendon. Eagles starting center Jason Kelce and now-right guard, Todd Herremans, will return to the lineup as well. The team also took Oklahoma offensive tackle, Lane Johnson, with the 4th overall pick in this year's draft.

The starting lineup is a very promising group, but with the offensive line's injury history, it is important that the unit has considerable depth in order to not repeat last year's disaster. Luckily for Chip Kelly and his staff, last year's problems led the way for several backup players to receive playing time. Of those depth players, now-second year offensive tackle, Dennis Kelly, may be the most vital to the unit's success. The 6'8" lineman started 10 games in 2012, filling in at guard and tackle for Herremans and embattled former first round pick, Danny Watkins.

Kelly experienced mix results during last season, but clearly improved throughout the campaign. The Purdue alum stood out on a line that featured fellow depth players such as Dallas Reynolds and King Dunlap, the latter of whom, Kelly hopes to replace at swing tackle. With a new coaching staff and blocking scheme, Kelly's experience from last year could be important in his quest to adapt to a larger role.

Kelly's development under new offensive line coach, Jeff Stoutland, will be critical to his immediate success. While he was selected early, Johnson, who has only been an offensive tackle for two college seasons, may need time to develop. Johnson's ability to assert himself as will directly impact Kelly. The second-year player could fill in at the starting right tackle spot, while Johnson acclimates himself to the big leagues, as well as play a big role for the team on goal line situations. Even if Kelly does not start for Johnson, the rookie could be used in roles that open up playing time for his more seasoned teammate. Reports out of OTAs seem to imply that Johnson could lineup in several spots on offense, which would mean that another lineman would need to fill in for him.

Kelly's youth is also a plus for the offensive line. Keep in mind, Peters, Mathis and Herremans are all in their early 30's and may not be on the roster in the next few years. Kelly has great shot at filling one of the trio's starting positions when one of those players moves on. With his experience at both guard and tackle, Kelly could also have a leg up on fellow reserve linemen. Also, being that Peters has missed 22 games in the last four seasons, it is likely that Kelly will get a chance to prove his worth at some point in 2013.

Kelly is obviously going to need to prove that he has staying power and impress the coaching staff, but last season's experience is a huge advantage for him. Already being subject to the trial by fire that was the 2012 season, Kelly is in prime position to improve his game. Whether he is starting or not, Kelly is set to play a major role for the offense and he needs to be ready for it. Only time will tell whether he is prepared for the challenge.