Mason's decision was announced two days after the funeral of McNair, a longtime friend who was shot and killed. Mason spoke at McNair's memorial Thursday.
"I have been thinking about this since season ended," Mason told jocklife.com, the Web site that first reported the announcement and shares the address of Mason's agent. "Emotionally I am just not that enthused. I have not been that enthused to get up and work out. ... It was getting to that point. This decision has nothing to do with the contract situation; I have made enough money, more than enough money.
"Emotionally, there are things that are more important. It's time right now. I don't know what's going to happen from here, but it's going to be really nice to see what life has in store for me. What I want people to remember about my NFL career is that I played hard ... played hard in practice and the game. I tried to make everyone better and would do anything to help."
Without Mason, there would be a huge hole in the Ravens' offense. Over the past two seasons, Mason has caught 183 passes - more than twice as many as any other Ravens receiver over that span.
Joe Flacco's top receivers would be Mark Clayton and Demetrius Williams, two players who have yet to meet expectations. The would-be third receiver, Marcus Smith, didn't catch a pass in his rookie season.
Clayton, one of Mason's closest friends on the Ravens, expressed disbelief when told of Mason's retirement.
"We don't know for sure," Clayton said. "I hope not, and I don't think it's true. I haven't heard that."
Only 16 days before veterans report to training camp, the Ravens' options to replace Mason are limited.
In gaining $3 million in salary cap room from Mason's retirement, the Ravens could sign a free agent. The top receiver available is Marvin Harrison, who had 60 catches and five touchdowns last season for the Indianapolis Colts.
Another possibility is revisiting a trade for Anquan Boldin or Brandon Marshall. The Ravens had talks with the Arizona Cardinals before the NFL draft about Boldin but considered the asking price (picks in the first and third rounds) too steep. The team also explored trading for Marshall, the Denver Broncos' wide receiver, but the Ravens' interest never became serious because of his legal troubles.
Mason said the Ravens don't necessarily need to add an additional receiver.
