The Patriots and Thuney have until July 15 to continue to negotiate a long-term contract. By signing the tender, Thuney also can now be traded to another team.
Thuney was expected to generate significant free-agent interest because of his combination of age (he turned 27 in November), durability and top-of-the-line play at left guard.
That's the ideal trifecta and why Thuney, who started every possible game over the past four seasons (74, including playoffs), was one of the best players on the free-agent market.
The reason for Thuney to sign the tender is that the Patriots could have rescinded the franchise tag, leaving Thuney with nothing -- as with what happened between the Panthers and cornerback Josh Norman in 2016. If that happened, with teams having already committed big free-agent dollars, it could have put Thuney in a spot where he couldn't fully experience the benefits of unrestricted free agency.
In 2019, Thuney had a 97% pass-block win rate, according to ESPN's metric that uses NFL Next Gen Stats to determine which linemen can sustain their blocks for 2.5 seconds or longer. That was second-best among all guards, behind perennial All Pro Marshal Yanda of the Baltimore Ravens (98%).
The Patriots selected Thuney in the third round of the 2016 draft out of NC State, moving him from tackle to guard. The selection (78th overall) was ultimately part of the compensation the team received for trading Pro Bowl defensive end Chandler Jones to the Arizona Cardinals.
Thuney became the first player in NFL history to start in the Super Bowl for the first three years of his career, according to the Elias Sports Bureau.
ESPN's Mike Reiss contributed to this report.