Hoyer, who had taken a free-agent visit with the New York Jets earlier this offseason as a possible backup to No. 2 pick Zach Wilson, opened last season as the Patriots' top backup before slipping to the No. 3 spot behind Stidham after the fourth week.
Hoyer, 35, provides backup quarterback insurance as a potential starting competition unfolds ahead of him. Coach Bill Belichick has declared Newton the top option at this time, while leaving the door open for Jones -- and possibly Stidham -- to challenge him for the starting role.
"Somebody would have to play better than [Newton] does," Belichick said on April 29.
The return of Hoyer, who has played for the team in three separate stints (2009-2011, 2017-2018 and 2020), provides the Patriots with flexibility and insurance, depending on how a starting competition plays out.
In training camp last year, Hoyer had arguably the most consistent performance among Patriots quarterbacks. That helped him initially beat out Stidham, who had been the No. 2 option in 2019.
Hoyer was unexpectedly thrust into a starting role a few days before the Patriots' Week 4 road game against the Kansas City Chiefs, as a result of Newton testing positive for COVID-19 the night before the team was scheduled to travel.
The Patriots lost 26-10 in a contest that was pushed back one day, with the team traveling on the morning of the game. Hoyer went 15-of-24 for 130 yards, with no touchdowns and one interception, and he had a notable breakdown at the end of the first half in taking a sack when the Patriots were out of timeouts, costing them a chance at a field goal attempt.
Hoyer also lost a fumble on a strip sack, which was his final play before Belichick replaced him with Stidham. From that point, Hoyer served as the Patriots' third quarterback the rest of the year.