Ex-NFL star Joe Theismann might be out-gruesomed for the most stomach churning sports injury of all-time ... thanks to Louisville's Kevin Ware.

But just in case, let's grab a bucket ... and rundown the contenders.

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NFL legend Joe Theismann -- famous for suffering one of the gruesomest career-ending injuries in sports history -- is optimistic about the recovery of Louisville basketball player Kevin Ware ... telling TMZ, Kevin's young enough to make a full comeback.

Theismann says he saw 20-year-old Ware's injury on TV Sunday night when it happened ... Louisville was playing Duke and Ware jumped to block a 3-pointer ... but he landed wrong on his foot and snapped his right shinbone through his skin.

Theismann -- whose QB career came to an end in 1985 when Lawrence Taylor snapped his leg like a twig during "Monday Night Football" -- tells us, "I got sick to my stomach ... It brought back a lot of memories that weren't very pleasant for me."

But Theismann says Ware's youth is a huge advantage in recovery ... but that's not all Ware's got going for him. Watch the video.

NFL Network analyst Joe Theismann says he wasn't shocked by the New Orleans Saints bounty scandal ... telling TMZ he was targeted for punishment way back in his Washington Redskins glory days.

Theismann -- who led the 'Skins to a Super Bowl victory back in 1983 -- was at LAX this weekend when we asked if he thought opponents ever tried to take him out of a game for a shot at an illegal cash bonus.

Joe replied, "Absolutely ... to be honest with ya, if you didn't have a bounty on your head when I played ... it means you weren't worth anything anyway."

Bonus! We also asked Joe which NFL QB is considered the best-looking guy in the league ... and, shocker, it WASN'T Tom Brady!