Teddy Bridgewater WILL BE BACK under center in an NFL game ... so says former star QB Joe Theismann -- who sustained possibly the most gruesome sports injury of all-time.
TMZ Sports spoke to the former Redskins signal caller -- who had his career ended after Lawrence Taylor snapped his leg back in'85 -- about Bridgewater's prospects of returning to the league after dislocating his knee and tearing his ACL at practice yesterday.
Good news Vikings fans ... Theismann says he fully expects T.B. will be the starting QB for Minnesota next season.