"I told them I would be good to go," Birk told the newspaper after a month of uncertainty about his future plans.
The six-time Pro Bowl selection has not missed a game during his two seasons in Baltimore despite battling knee, neck and elbow injuries. He has a year remaining on his contract.
"The older you get, the more beat up you get," Birk said. "When you have injuries, it's hard to remember what it's like when you feel good. It's part of the deal. It's what you signed up for. The older you get, the more you have to embrace that part of the challenge. Otherwise, it comes to the point where you say you can't do it anymore."