Tom Brady Defends Business Partner Despite Controversial Past

— -- Superstar quarterback Tom Brady swears by his personal trainer and business partner, Alex Guerrero.

Brady credits Guerrero for helping to keep him on the field.

And the four-time Super Bowl champion is standing by his fitness guru, amid a Boston Magazine report about Guerrero’s past, that the Federal Trade Commission sued Guerrero over his false claims about dietary supplements in an infomercial.

Guerrero falsely claimed in an infomercial that a product called Supreme Greens could cure or prevent cancer, heart disease and diabetes, according to a 2004 complaint filed by the FTC.

“And now here’s the question: If I alkalize my body, am I going to come up with one of these chronic degenerative diseases?” the infomercial co-star asks Guerrero.

“No,” Guerrero says.

“Such as cancer, arthritis …”

“No.”

“How can you say that so confidently?”

“I’m very confident in saying that, primarily because of the clinical studies we’ve done. I’ve seen it in my – in my – in my clinical practice. I’ve seen it every day in my clinical practice,” Guerrero says.

The FTC found there was no real evidence to support Guerrero’s product, something he admitted to ABC’s “20/20” in an April 2004 interview.

“No, there is no scientific support of Supreme Greens,” he said.

At the time, Guerrero told “20/20” that the production company behind the commercial twisted his words unfairly to make his vegetable supplement seem like a miracle pill.

Guerrero agreed to a settlement in 2005 that permanently prohibited him from pretending to be a doctor – or selling or distributing supplements that claim to “prevent, treat, or cure any disease.” Guerrero was also forced to pay $65,000 or hand over the title of his 2004 Cadillac Escalade ESV in the settlement.

But since that time, Guerrero has become one of Brady’s closest advisers, serving as godfather to Brady’s younger son, Ben.

The friends operate a sports therapy center, TB12, with its headquarters near Gillette Stadium, where the Patriots play.

Brady, 38, defended his friend in a Monday interview with WEEI’s “Dennis and Callahan” program.

“I wouldn't be playing today if it weren't for what he's been able to accomplish with me,” Brady said.

Brady told WEEI that Guerrero’s holistic approach is the key to his success, which includes more than 400 career touchdown passes.

“Now you guys may think I'm full of crap, but the proof's what you see on the field,” Brady said.

Guerrero has not responded to ABC News’ requests for comment, and has not publicly responded after the release of the Boston Magazine article.

Brady passed for 275 yards and two touchdowns, as well as a touchdown run, in New England’s 30-6 victory over the Dallas Cowboys Sunday.