Starters: Donald Penn, Menelik Watson
Depth: Austin Howard, Matt McCants
The team wasn't jumping at the chance to bring back Donald Penn at left tackle, but ended up doing so once he tested his market. Menelik Watson will get the first shot at starting at right tackle with Austin Howard once again competing for the job once he returns form the knee injury he suffered late last season. McCants will once again compete to be the utility backup at right tackle/guard.
There is something to be said for having starters in place on both sides. On one side you have the stalwart Penn and on the other side you have the combo of Watson and Howard. This could turn out well or it could blow up in the Raiders' face.
Watson was injured in preseason (again) last year and missed the entire season. Luckily the Raiders had Austin Howard -- who was moved back to right tackle after playing guard for a season -- to step in and fill the spot.
All went well over the first half of the season, but the latter half saw things fall apart. Penn was not the same player he had been over the first 24 games in a Raiders uniform and is about to turn 33. Howard had his issues as well and eventually joined Watson on injured reserve.
A potential wildcard here is Kelechi Osemele, who the team would like to keep at guard, but should the need arise, could move to tackle. That would, of course, weaken the guard position, so that it not preferable. Not to mention, making a late position switch doesn't bring out the best in a player, especially when the move is from inside to outside along the offensive line.
Adding an offensive tackle even with the 14th overall pick would do a lot to strengthen the position right now as well as for the long haul. Penn isn't getting any younger, Watson hasn't shown he can stay healthy, and if this season he somehow does stay on the field, it would make Howard one of the most expensive backups in the league.