Mason will be released when the league calendar permits it. Sources told ESPN NFL Insider Adam Schefter on Monday that Baltimore also has told running back Willis McGahee and tight end Todd Heap they will be cut.
Defensive tackle Kelly Gregg also will be released, according to multiple media reports.
Mason, 37, was the most productive of the veteran foursome last season; the 15-year veteran caught 61 passes for 802 yards and seven touchdowns. Mason's production dropped in the first season since Baltimore added Pro Bowl wideout Anquan Boldin last offseason.
"It's a little bittersweet," Mason told The Baltimore Sun. "I understand the business of football, and I understand what has to be done in the business of football. It was good while I was there. I can't hang my head down. I think I did everything above and beyond what they asked me to do when I came in there six years ago. And I think everybody in that building can attest to that. If last year truly was my last year in a Ravens uniform, then I've enjoyed every bit of it."
Mason signed with the Ravens in 2005 after nine seasons with the Tennessee Titans. Despite playing in a run-oriented offense for much of his six seasons in Baltimore, he accumulated four seasons with at least 1,000 receiving yards.
Mason told The Sun that he would be open to returning to the Ravens, but regardless plans to play a few more seasons.
"This is just another chip on my shoulder," Mason told The Sun. "This is something else that fuels me and makes me try to be as productive on the field as I can, whether that be in Baltimore -- and I hope it is -- or somewhere else. [My return] is solely up to them. I love Baltimore. The city embraced me. The organization is great from top to bottom. My first thing would be: 'Why not Baltimore?' They're primed to win a Super Bowl and I don't want to go nowhere else but a place that is primed to contend for a Super Bowl."
McGahee played in 15 games last season, but had a career-low 100 rushing attempts for 300 yards. The 29-year old Miami product saw his rushing touchdowns drop from 12 to five as Ray Rice continued to take a majority of the Ravens' carries.
The 31-year-old Heap, a two-time Pro Bowler, caught five touchdowns amid 40 receptions and 599 yards last season. He played in just 13 games, however, after suffering a hamstring injury against the Steelers in December.
The Ravens drafted Heap with the 31st overall pick in 2001 out of Arizona State. He has 41 touchdowns catches over 10 seasons with Baltimore.
Baltimore fullback Le'Ron McClain is also scheduled to be free agent.
With the lockout over, the league has set a 4 p.m. ET deadline on Thursday for players to be cut or waived.
Information from ESPN NFL Insider Adam Schefter and The Associated Press contributed to this report.