by Rick Drummond , Profootballfocus.com It’s best to refer to this group as a work in progress. Unfortunately for the Raiders, it has been in that state for several seasons now. In obvious need of an improvement over their 2009 output, the Raider O-line had to be overhauled. Recognizing that, the Raiders began the multi-season process by letting Cornell Green walk in free agency, selecting two linemen in the draft, and hiring a play-caller which freed Tom Cable to spend more time assisting with the line. Four of 2009’s five regular starters returned for 2010 with Green’s former spot at right tackle being the only immediate opening. Langston Walker won that job in camp and held it all season. Khalif Barnes, who was also in the running for the vacated right tackle spot, settled in as the utility player, spending the majority of his time checking into the game as an extra lineman / tight end. Of the four returning starters, only Robert Gallery at left guard was viewed as a fixture, leavin...