More Position Reviews:Quarterbacks, Safeties

Overview:Through the majority of 2015, the offensive line was arguably the Raiders most consistent and top-performing position group.

The big guys up front were stellar in pass protection, giving second-year quarterback Derek Carr time to operate, and also helped spark the run game as well.

They maintained their high level of play as the season wore on, even after several injuries at center and along the right side of the line forced a variety of personnel changes.

Tackle Donald Penn and guard Gabe Jackson were exceptional on the left side of the line, and even after the aforementioned position changes along the right side, offensive line coach Mike Tice's unit did a good job of keeping Carr upright and kept the Silver and Black offense moving.

By The Numbers:The Raiders offensive line allowed just 33 sacks in 2015 which was tied for the 11th-fewest in the NFL.

Going Forward:As of now, three of the team's five starting offensive linemen are under contract for next season.

The two exceptions? Left tackle Donald Penn and right tackle J'Marcus Webb.

Penn has been impressive during his two seasons as a Raider and has built up quite a rapport with Carr, although he's scheduled to become a free agent when the league year begins March 9.

Webb is in a similar position, as he's eligible to become a free agent as well after one year in the Silver and Black.

General Manager Reggie McKenzie selected Jon Feliciano in the fourth round of the 2015 NFL Draft, and he began to play a larger role in the last quarter of the season

Also, waiting in the wings? Tackle Menelik Watson who was placed on Injured Reserve before the Raiders final preseason game last September.

Watson should be a player to keep an eye on going forward for the Raiders. In limited action he's played well, and if he can stay healthy he could be in the mix for a starting job along the offensive line in 2016.

The interior of the Raiders line is intact; it's just the future of the tackles that pose a question going forward.

Standout Performer:Left tackle Donald Penn.

Penn was impressive once again in 2015 and served as the anchor of the offensive line.

He played at a Pro Bowl level this season, and was not only a leader on the field but served as a quality veteran presence on a predominantly young team.

Sometime in the near future, McKenzie will face a tough question about what to do with the 32-year-old tackle.