Seferian-Jenkins had signed a modest one-year, $895,000 contract on April 10, and he was vying for a roster spot at a position where the Patriots are transitioning without the retired Rob Gronkowski. The contract included just $50,000 in guaranteed money.
Seferian-Jenkins wasn't at the team's mandatory minicamp Tuesday, with coach Bill Belichick foreshadowing his release by saying that all players who were required to be present had reported.
The 26-year-old Seferian-Jenkins, who has 116 career receptions for 1,160 yards and 11 touchdowns in 43 games over five seasons, also wasn't present during a voluntary practice in May that had been open to reporters.
Veteran Benjamin Watson headlines the Patriots' depth chart at tight end, but he will miss the first four games of the season because of an NFL suspension for banned substances.
Seferian-Jenkins had 11 catches for 90 yards and a touchdown before going on injured reserve in early October with a core muscle injury that required surgery. He became a free agent when the Jacksonville Jaguars declined his $500,000 option for 2019.
He joined the Jaguars on a two-year, $10 million deal before last season after resurrecting his career with the New York Jets. The Tampa Bay Buccaneers cut him after a September 2016 drunken driving arrest, which ultimately resulted in a two-game suspension by the NFL at the start of the 2017 season.