Barnes agreed to a one-year contract. Terms of the deal weren't available. Barnes had been in talks with the Bucs late last week but opted to go with the Raiders, who were recruiting him hard to be a possible starter along the offensive line.
With Kwame Harris released, the Raiders' left tackle position is open, and Barnes will be given the opportunity to compete for the starting job. Barnes was a second-round pick of the Jaguars who has been starting at that position since his rookie season.
"I think this is a great opportunity and place for me to start fresh," Barnes said. "I'm excited to be part of helping this franchise get back on top and I will have a shot to be the starter at left tackle and that's all I can ask for. I have a lot to prove and I'm betting on myself by agreeing to a one-year contract. [Raiders owner] Mr. [Al] Davis has a track record of taking care of his own guys and he promised me the same, if I take care of my business on and off the field."
John Clayton is a senior NFL writer for ESPN.com.