As Tom Brady and Bill Belichick battle toward a sixth Super Bowl championship, a rift may be growing between the future Hall-of-Fame quarterback and head coach.

The Boston Globe reported Tuesday that special privileges the Patriots had granted to Brady's personal trainer, Alex Guerrero, were revoked three weeks ago. Before Belichick's decision, Guerrero had been allowed to fly to road games on the team's charter jet, and he had sideline access at games.

Guerrero, a close friend of Brady's and the godfather of his son, worked with the quarterback to launch the TB12 Center near Gillette Stadium in 2013. Since then, the Globe reports, many of Brady's teammates trained with Guerrero, with the bill going to the Patriots. In what the Globe calls "a unique arrangement" within the NFL, by this season, the majority of the Patriots roster was on Guerrero's client list.

The trainer has an office near the Patriots locker room at Gillette Stadium. He is reportedly no longer permitted to treat players besides Brady there.

Brady was asked Monday about a potential rift between his coach and his trainer on WEEI.

"I don't have any comment on that other than to say Alex, it's been well-documented, has been a huge part of what I do and I'm so fortunate to have him not only as a friend, but with everything that we've been able to do together," Brady said. "Alex has been a huge, huge reason why I'm still playing."

Belichick did not address the issue when he spoke to WEEI Monday, and Guerrero did not respond to the Globe's request for comment.

According to the Globe, Guerrero began working with Patriots linebacker Willie McGinest more than 17 years ago, beginning his relationship with players on the team. His relationship with Brady became especially close in 2008 after the quarterback's season-ending knee injury in the first quarter of Week 1.

In 2010, Brady endorsed a drink that Guerrero's supplement company's marketing claimed "protects your brain from the consequences of sports-related traumatic brain injury," a notion the Federal Trade Commission deemed unfounded. The company was ordered to stop marketing the product and issue refunds.

His work is admittedly polarizing. Guerrero told the New York Times Magazine in 2015 that conventional NFL team trainers clashed with his methods "most of the time," adding that "everyone thinks I'm a kook and a charlatan."

The Patriots are 11-3 and sit in position to lead the AFC at the end of the season after a shocking comeback win over the Steelers on Sunday.