Mankins, who turns 34 on Thursday, has played the past two seasons in Tampa Bay following a trade from the Patriots.
"It is always difficult losing a player of Logan's caliber both on the field and in the locker room," Buccaneers general manager Jason Licht said. "He is one of the toughest, most intelligent and skilled players at his position that I have seen in my years around this game. Logan distinguished himself as the ultimate professional over his 11-year career and he was an unquestioned leader for us over the past two seasons. His leadership, work ethic and selflessness played a key role in the development of our younger players and he set the standard which we use to evaluate all of our offensive linemen."
The seven-time Pro Bowl selection, including last season for the Buccaneers, played his first nine seasons in New England.
Mankins was voted an offensive captain before last season. He helped mold an offensive line that started two rookies into a unit that paved the way for running back Doug Martin and protected rookie quarterback Jameis Winston. Martin ran for 1,402 yards and was named to the Pro Bowl this past season, and Winston became just the third rookie in NFL history to throw for more than 4,000 yards.
In 2011, Mankins tore his ACL in the season opener and played the rest of the season with the injury, sources had told ESPN NFL Insider Adam Schefter. Mankins later said, "It wasn't 100 percent but it was still functionable. I could still run, so there was no reason to sit out. There were no MRIs or anything, so we never knew exactly what was hurt. If you can still run and play, there is no reason to go see a doctor, right?"
An MRI after Super Bowl XLVI revealed the exact nature of the injury, which surprised Mankins, who joked his approach was "put a brace on, tape aspirin to it, and go."
After the Patriots traded Mankins, New England coach Bill Belichick had high praise for him.
"Logan Mankins is everything we would ever want in a football player. It is hard to imagine a better player at his position, a tougher competitor or a person to represent our program. He is one of the all-time great Patriots and the best guard I ever coached," he said. "Logan brought a quiet but unmistakable presence and leadership that will be impossible to duplicate. Unfortunately, this is the time of year when difficult decisions have to be made -- and this is one of the most difficult we will ever make -- but like every other decision it was made for what we feel is in the best interests of the team."
Mankins was scheduled to enter the final season of the six-year, $51 million contract he signed in 2011 when he was with the Patriots. He was to receive $6,750,000 in base salary, but he had no guaranteed money left. The Buccaneers will save $7 million under their salary cap with his decision to walk away from the NFL.
ESPN's Mike Reiss contributed to this report.