Birk, 35, is an unrestricted free agent after completing his 14th season in the NFL. He had contemplated retirement at the end of last season before coming back to Baltimore.
"The Ravens need to know at a certain point to make their plans moving forward," Birk said from the Super Bowl, where he is a finalist for Walter Payton NFL Man of the Year Award.
A six-time Pro Bowl performer, Birk has been one of the most reliable linemen in the NFL, starting 96 consecutive games. That the NFL’s second-longest active streak among centers.
It's been a challenge to stay in the lineup in recent years with the Ravens. He's battled neck, elbow and knee injuries and still feels the effects of it today.
"When you're in your 20s, you're indestructible and feel bulletproof," he said. "Now, it takes a lot longer to bounce back. I know I have the passion to come back. I will always have the passion."
If Birk returns, he wants to come back to Baltimore, where he has played the past three seasons. "I made it clear that's my first choice," Birk said.
General manager Ozzie Newsome said at the state of the Ravens address this week that the team will add a center regardless of Birk's decision. “I will say this: Before we line up and play in 2012, there will be another center on this football team in some capacity -- free agency, draft or whatever,” Newsome said.
Birk has made as much of an impact off the field as he has on it for Baltimore. Birk's "Ready, Set, Read!" program, an initiative of his H.I.K.E. Foundation (hope, inspiration, knowledge and education), reaches close to 100,000 children in the Baltimore area and motivates students to read at home through an incentive-based system.
“It’s hard to exactly put into words what it means to be nominated for an award that has Walter Payton’s name on it,” Birk said. “It speaks to the tradition that NFL players have to use the platform that football provides us to get out there in the community, try to be positive role models and make a difference. This is a great honor.”