Defensive end is a difficult position to project without knowing what the new coach's system is going to be. For instance, a guy like Bryce Cottrell goes from being a 4-3 defensive end to a 3-4 outside linebacker, while somebody like Hassan Ridgeway likely transitions from defensive tackle to a 3-4 defensive end. But for the purpose of this article, we'll focus more on if Texas sticks with a 4-3.
In that case, Texas is in deep trouble if star end Cedric Reed elects to go to the NFL. Reed's return would give the Longhorns a potential All-American from the word go, and in any system. He's long enough and physical enough at the point of attack to play a two-gap end spot in a 3-4, though his best spot might be as a strong-side end in the 4-3, which is what he played this season.
If Reed returns, Texas has both the talent and the depth to fill this group out. Shiro Davis has shown flashes, and he has the athleticism to be very good at a weak-side end spot. Caleb Bluiett saw some time late in the season and could also rotate through. And then, one of either Bryce Cottrell or incoming freshman Derick Roberson could provide a fourth end to come in and help supply pressure on passing downs, if the Longhorns elect not to move an outside linebacker down for those kinds of situations (somebody like Naashon Hughes, for example, or even Steve Edmond).
Sione Teuhema has potential as a long, rangy athlete who has quickness around the edge, though he isn't as polished as Roberson is, and will likely need a redshirt.
Really, either way, Texas should probably go out and pursue a junior college talent at the position, somebody who could, at worst, add quality depth and at best, provide a potential starter if Reed elects to go to the NFL. The wild card in this situation is Solomon Thomas. Out of a stacked 2014 defensive end class in-state, Thomas is probably the most college-ready. Can the new staff get him to come to the 40 Acres? He's still apparently open to the idea.
In 2015, Texas currently sits in a great spot for James Lockhart, which is fantastic given that there just aren't a ton of impact ends in-state in that class just yet. Find a way to land Thomas in 2014 and Lockhart in 2015, and Texas is in an outstanding position with young talent with those two, Roberson and Teuhema. It would help if the new coach could potentially cast his nets out of state and land somebody like 2015 recruit Keisean Lucier-South, a five-star Californian who currently has the Longhorns high on his list.