The reason they let Gaither walk is that they drafted Michael Oher.
Originally Posted by DMN
Gaither is not a right tackle. He's a left tackle. The problem is that Oher is a better left tackle. So, the Ravens could either start Gaither on the left and put Oher on the right, and use both guys, or they could put their best left tackle into the game and ditch Gaither. His injury concerns didn't help at all.
Gaither also made the decision easier by wanting to be paid like a left tackle.
the raiders never signed gaithers cuz of back problems. which is why the ravens let him go. he missed all of last season cuz back injury.