Mayo made the announcement during a team meeting, and the 31-year-old Brissett will take the reins in the season opener against the Cincinnati Bengals on Sept. 8.
Brissett beat out first-round draft pick Drake Maye, even though Mayo said earlier this week that Maye outplayed Brissett during the preseason and had closed the gap for the job.
Maye, the No. 3 overall pick in the 2024 draft, threw for 192 yards and one touchdown in the preseason.
The Patriots will mark fourth team that Brissett has played for in the past four seasons after seeing action with the Miami Dolphins, Cleveland Browns, and Washington Commanders.
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It is also his second stint with the Patriots. He played the 2016 season with New England after they drafted him in the third round of that year’s draft and also spent four seasons with the Indianapolis Colts.
Entering his ninth NFL season, Brissett has an 18-30 record as a starter, completing 61% of his passes for 10,574 yards, with 51 touchdowns and 23 interceptions.