Patrick Mahomes Can Be Best QB Of All-Time, Says Dick Vermeil

Move over Tom Brady ... Dick Vermeil tells TMZ Sports he won't be surprised if we're all callin' Patrick Mahomes the new GOAT by the time his career reaches its end.

"I think he has a chance to go down as one of the ... if not the finest," the legendary coach says.

Patrick lit up the Rams for 478 passing yards and 6 TDs Monday night ... and when we spoke with Dick about the performance Tuesday -- he couldn't have been more impressed.

In fact ... Vermeil -- who previously coached both the Rams and Chiefs -- says he'd straight-up take Pat over Jared Goff and any other young QBs in the league right now.

"I've never seen anything like him," Vermeil says ... "He can do it all. He can throw off balance, upside down and backwards and throw a completed pass. He has unbelievable poise."

"I don't see any limitation."

Vermeil says it's Mahomes' age that impresses him the most, telling us a 23-year-old in his 2nd year shouldn't be able to do the things the Chiefs star is currently doing.

"He's way ahead of everybody else at the same time!"

We also spoke with Dick about the Rams ... and he loves them too -- but says Goff and the guys still have some proving to do before they can be compared with his old Rams squads.

By the way, if you notice the Chiefs logo on Dick's shirt -- he swears he's not picking favorites ... it's just "gym clothes."