Bruce Gradkowski

When Raiders coach Tom Cable addressed the full team for a year-end wrap-up Monday, two of those quarterbacks weren’t in attendance.

Charlie Frye was getting an MRI exam for what is believed to be a lower back strain. And Jamarcus Russell? He had an excused absence for “personal issues.”

Cable declined to state what those issues are. And though they may have been perfectly valid, even unavoidable, it was yet another red flag in the file of a young quarterback who is shaping up to be one of the great underperformers in NFL history. Russell, a former No.1 overall draft choice who started the first nine games before giving way to journeyman Bruce Gradkowski, finished the season with a passer rating of 50.0. It was the NFL’s worst for a qualifying quarterback since three of them — San Diego’s Craig Whelihan and Ryan Leaf, and Philadelphia’s Bobby Hoying — came in below 50 in 1998.