Vrabel hired McMillan in 2021 as a defensive assistant where he primarily worked with Titans outside linebackers. In 2022, he worked as a defensive line assistant coach alongside Williams, who was named the Patriots defensive coordinator. McMillan continued to work with Titans defensive lineman in 2023.

The New England Patriots formalized the hiring of John Streicher, who NFL insider Albert Breer described as Mike Vrabel's "right-hand man." Streicher spent six seasons with the Tennessee Titans under Vrabel in a multitude of roles,

Williams reunites with coach Mike Vrabel in New England after working on Vrabel's staff for six years with the Titans.