Brady has previously said he would like to play until he's 40. After practice Sunday, he wouldn't put a number on how many more years he has left, just reiterating that he would "like to play for a long time."
Nick Caserio, the Patriots' director of player personnel, could remember a few great players who made it to 40 or farther. Great players often combine conditioning, smarts and a love for football to remain effective into their late 30s and beyond, he said.
"Joe Montana was a great player, [Dan] Marino was a great player, [John] Elway was a good player, [Troy] Aikman — those guys were fun to watch for years," he said.
Quarterback George Blanda played until he was 48, Steve DeBerg to 44 and Brett Favre until he was 41.
Caserio cited two other examples. Vinny Testaverde was 42 when he played for the Patriots in 2006, and Doug Flutie was 43 when he played for the Pats in 2005.
Brady said after practice Sunday that he has a lot of football left in him, and that both Flutie and Testaverde were great teammates from whom he learned a great deal.
"I'm a long ways from 42," Brady said. "Hopefully, I'm still talking to you guys when I'm 42."
Four-year veteran Brian Hoyer and second-year pro Ryan Mallett are competing to one day replace Brady or to step in if he should go down again, as he did in 2008.
"I think they're going to have ample opportunity here in the preseason, so we'll get a good gauge," Caserio said.
Mallett spent much of his rookie season trying to catch up after the lockout eliminated rookie camp and OTAs.
"I think having a spring under my belt and going back to Day One of how we do things is the kind of stuff that I missed last year from Day One," he said. "So I was trying to play catch-up [last year], and it's hard to play catch-up in this offense."
Mallett said his increased comfort level has shown itself during camp. Coach Bill Belichick agrees.
"He's way ahead of where he was last year," Belichick said. "[He] knows more about what we're doing. I think has a better understanding of what the defense is doing and has run the plays — he's actually run them. Last year, we were putting them in and he had never done them before."
The Patriots pretty much know what they have in the 26-year-old Hoyer, who will be an unrestricted free agent after the 2012 season and could earn a major opportunity elsewhere.