Patriots star receiver Julian Edelman, who helped New England win three championships and was the MVP of Super Bowl LIII, announced his retirement in a video posted on social media Monday.

The NFL transaction wire released Monday stated that Edelman had his contract terminated by the Patriots, but the roster move is expected to be a technicality as part of his retirement, a source told ESPN.

"It was a hard decision, but the right decision for me and my family," Edelman said. "And I'm honored and so proud to be retiring a Patriot. ... It's been the best 12 years of my life."

Edelman, who turns 35 next month, was limited to six games last season because of a chronic knee injury. He spent his entire 12-year career with the Patriots and ranks second in NFL history with 118 postseason receptions, behind only Jerry Rice's 151.

Foxboro Forever pic.twitter.com/x3SDDPJoTX

— Julian Edelman () April 12, 2021

One of Edelman's signature plays was an improbable diving catch in Super Bowl LI, helping the Patriots overcome a 28-3 second-half deficit to rally past the Atlanta Falcons. Two years later in a victory over the Los Angeles Rams in Super Bowl LIII, he was named MVP after totaling 10 receptions for 141 yards.

His quarterback for those games, Tom Brady, took to social media Monday to praise his longtime slot receiver.

"On the biggest stage and in the biggest moments, you always came through," Brady tweeted. "You never lost that chip on your shoulder and you never let anyone define you as a person or player. I'm proud of you Jules. Love you."

Added Patriots chairman and CEO Robert Kraft in a statement: "Julian Edelman is one of the great success stories in our franchise's history. There aren't many players who earn an NFL roster spot at a position they have never played before. Julian not only did that as a seventh-round draft selection, but he is retiring with the second-most career receptions in franchise history and as a three-time Super Bowl Champion, including his last as Super Bowl MVP. No one was more committed to his craft and honing his skills than Jules. His explosiveness off the line, quickness in his cuts and elusiveness after the catch made him one of the hardest players to defend throughout his career."

Edelman caps his career in second place on the all-time Patriots chart for receptions (620), behind only Wes Welker (672). He is fourth on the team's career receiving yards list with 6,822 receiving yards, behind only Stanley Morgan (10,352), Rob Gronkowski (7,861) and Welker (7,459).

"Nothing in my career has ever come easy and no surprise, this isn't going to be easy either," Edelman said. "I've always said, 'I'll go until the wheels come off.' And they finally have fallen off. Due to an injury last year, I'll be making my official announcement of my retirement from football."

By having his contract terminated for a "failed physical," Edelman now becomes eligible for the injury protection benefit, per the CBA, available to all players in this situation. Edelman can collect up to $2 million through this benefit.

Few would have predicted his career trajectory when the Patriots selected Edelman in the seventh round of the 2009 draft -- 232rd overall. Edelman was a quarterback at Kent State, with his running skills and quick-cutting ability catching Bill Belichick's eye as a possible receiver/punt returner.

Edelman was still playing at a high level last season, totaling a career-high 179 yards in a Week 2 loss to the Seahawks. But the nagging knee injury ultimately landed him on injured reserve in late October, and while there was hope he might return late in the season, he wasn't healthy enough to be activated.

Because of his health, the Patriots went into the 2021 offseason unsure of Edelman's status, which contributed to their agreeing to contracts with receivers Nelson Agholor (two years, $26 million, with $15 million guaranteed) and Kendrick Bourne (three years, $22.5 million, with $5.25 million guaranteed) on the first day of free agency. Edelman was also entering the final year of his contract.

Edelman's clutch postseason play is reflected in his six games with at least 100 receiving yards, tied with Michael Irvin for second all-time (Rice is first with eight).

"By any measure of what constitutes an elite NFL career -- wins, championships, production -- Julian has it all," Belichick said in a team statement. "Few players can match Julian's achievements, period, but considering his professional trajectory and longevity, the group is even more select. It is historic. This is a tribute to his legendary competitiveness, mental and physical toughness and will to excel. Day in and day out, Julian was always the same: all out."

The Patriots tapped into his old quarterback skills with success, with Edelman completing 7 of 8 passes over his career for 179 yards, with two touchdowns and a perfect 158.3 passer rating (includes playoffs).

Against Denver last October, Edelman joined running backs Andy Johnson (Sept. 6, 1981 vs. Baltimore) and Dick Christy (Nov. 18, 1960 vs. Dallas Texans) as the three Patriots non-quarterbacks who have completed two passes in a game.

Over his career, Edelman totaled 58 rushing attempts for 413 yards, the most rushing attempts and rushing yards by a wide receiver in Patriots history.

In the latter stages of his career, Edelman, of Redwood City, California, publicly embraced his Jewish identity, taking pride in becoming the first Jewish player to be named a Super Bowl MVP.

In July 2020, he invited receiver DeSean Jackson to the United States Holocaust Memorial Museum in Washington, D.C., after Jackson's anti-Semitic social media posts. This past March, he wrote an open letter to Miami Heat center Meyers Leonard about Leonard's use of an anti-Semitic slur during a video game livestream.

ESPN Senior Writer Adam Schefter contributed to this report.