Warren Moon knows a thing or two about longevity, having played quarterback in the NFL until he was 44 years old. So his opinion on Tom Brady’s performance at age 41 definitely carries weight.

That said, Skip Bayless couldn’t help but wonder Thursday on FS1’s “Undisputed” whether the Hall of Famer’s recent comments about Brady stemmed more from jealousy than from what he’s seen from the New England Patriots quarterback this season.

Moon, who was among several former NFL players who spoke with Bleacher Report’s Tyler Dunne for a feature on Brady, suggested there’s some deterioration coming for the Pats QB, albeit gradually. Brady’s numbers are down across the board this season — his 18th in the NFL — and Moon believes this is the product of several developments.

“Most people think with a quarterback, it’s your arm,” Moon told Dunne. “Your arm is important, but if you don’t have your legs working with the rest of your body — being able to have those quick-twitch movements to move in the pocket to slide and buy yourself a bit more time — those are the things you start to see that don’t happen as fast.

“That’s where Tom used to excel. Even though he’s not a great athlete, a scrambler or anything like that, he could really slide and move around the pocket as well as any quarterback and manipulate the pocket. Those things are starting to slow down a little bit more for him as he gets a little bit older.”

Brady already has appeared in more regular-season games than Moon, who began his NFL career at age 27 and lasted 17 years in the league. He’s also said in the past he’d like to play into his mid-40s.

Is that enough for Moon to feel “a little threatened” by Brady, like Bayless suggests? Probably not. But it’s a juicy theory, at the very least.

Thumbnail photo via Steve Mitchell/USA TODAY Sports Images