FOXBOROUGH, Mass. -- Brian Belichick, who spent the past five seasons as the New England Patriots' safeties coach, will not return to the team in 2025, according to a league source.

Belichick, the youngest son of former Patriots coach Bill Belichick, grew up a fan of the team and spent the past nine years on staff -- first as a personnel assistant (2016), then a coaching assistant (2017-19), before being elevated to safeties coach in 2020.

"He just brings a different level of how he sees the game, how he thinks the game," safety Jabrill Peppers said in 2024. "He holds us to a very high standard and has coached a lot of great DBs back there."

The Patriots' coaching staff is in transition for the second year in a row. New head coach Mike Vrabel replaced Jerod Mayo following a 4-13 season.

Vrabel hired former Titans and Lions defensive line coach Terrell Williams as his defensive coordinator. There was a question of whether Vrabel would consider retaining Belichick and cornerbacks coach Mike Pellegrino to pair with Williams, with Pellegrino's status uncertain.

Bill Belichick enters his first season as head coach at the University of North Carolina, where his oldest son, Steve, will serve as an assistant coach. Bill Belichick was out of football in 2024, while Steve Belichick served as defensive coordinator at the University of Washington last season.

One theme among new defensive assistants is ties to Vrabel from his tenure as Titans head coach (2018-23), with Clinton McMillan and Zak Kuhr set to join the staff, according to sources.

Other parts of Vrabel's staff are also being put into place, with former Bills and Jaguars head coach Doug Marrone and former Bears interim head coach Thomas Brown among the key hires on offense to work under coordinator Josh McDaniels, according to sources.

Vrabel also retained special teams coordinator Jeremy Springer and top special teams assistant Tom Quinn.