Despite an impressive collection of returning talent, the 2014 Oregon Ducks have some notable holes in the roster to plug: versatile, do-everything running back De'Anthony Thomas; wide receiver Josh Huff; cornerback Terrance Mitchell.
However, the most crucial vacancy in the lineup for head coach Mark Helfrich and his staff to fill is that which defensive lineman Taylor Hart leaves.
Defensive line is a general concern for Oregon this offseason, as Hart is just one of three departing defensive linemen who played central roles in the Ducks' 3-4 hybrid scheme. Oregon also loses Wade Keliikipi and Ricky Havili-Heimuli, further upping the stakes for new defensive coordinator Don Pellum and defensive line coach Ron Aiken this offseason.
Rebuilding the line starts with replacing Hart, the unit's foundation. That won't be easy—Hart was a three-year starter and four-year primary contributor. A recently retired Oregon defensive coordinator told The Oregonian, "I’d like to clone him and have 22 of him."
Oregon may not have 22 Harts, but it does have at least one defensive lineman ready to step up as the unit's anchor in tackle DeForest Buckner.
Buckner broke into the starting lineup down the stretch of his sophomore campaign and settled in over the season's final month. He finished the season with 3.5 tackles for loss and 2.5 sacks and was also a decided bright spot in losses at Stanford and Arizona.
At 6'7", 286 pounds, Buckner is of similar size to Hart and has the same ability to play both tackle and end. However, he'll best serve the Ducks at tackle next season, which leaves the end position open.
Discussion of Oregon's defensive end must start with Arik Armstead, a 5-star defensive line prospect in Oregon's 2012 signing class, who started for the first half of 2013. A wrist injury hindered his sophomore-year progress and he enters spring practices with his defensive future in doubt.
Armstead's unspectacular first two years on the defensive line have prompted talk of him moving to offensive tackle. NFL.com's Dan Greenspan hinted at the transition following Armstead's announcement he is focusing exclusively on football, and the ESPN.com Pac-12 blog tweeted the idea during the 2013 season.
Helfrich discussed the possibility with Andrew Greif of The Oregonian, and Armstead's performance in spring practices would seemingly go a long way in deciding where he plays next season:
[Offensive line coach] Steve Greatwood is trying to get the recruiter of the year award trying to work Arik every day. [Armstead]'s definitely a guy who has a prototype of that position [offensive tackle] but he’s also a guy who at times has been dominant defensively. He’s got to get better at what he’s doing but we’ll see where that takes him.
A change of positions for Armstead could move Buckner to end, with Sam Kamp—who saw opportunities late last season—sliding in at tackle. T.J. Daniel will also be a candidate to watch at defensive end.