Oakman -- once projected as a top NFL draft pick -- had his football career derailed when a fellow Baylor student claimed the football star raped her in 2016.

The case went to trial ... and Shawn was found NOT GUILTY (the jury only needed 45 minutes to deliberate) earlier this year. Still, the allegation caused him to go undrafted ... costing him time in the NFL and millions of dollars in salary.

Now, Oakman -- who's 27 years old -- is getting a new opportunity to play big-time football with the XFL's Los Angeles Wildcats.

We talked to Oakman ... and it's clear he's not content just collecting a paycheck -- he wants to go down as literally one of the greatest players of all-time.

"It only takes one great year," Oakman says. "A year here, a year there, next thing you know, they're gonna be talking about gold jackets."

"In 5 years I'll be 32? Why not?"

If you're not familiar with the 6'9, 280 lb. Oakman -- aside from destroying dudes on the field -- he also shot to internet superstardom a few years back when a photo of Shawn in his Baylor uni went viral ... sparking endless hilarious memes.

He was a beast then ... and Oakman says he's gonna be even BETTER now.

"I'm definitely ready to show the world that I got a lot more to give to the game than I did before."

As for how it feels to finally put the pads back on ... Oakman says "It's definitely surreal. It's a surreal feeling that you really can't explain. It's like, Cinderella with her glass slipper, you just turn into a beautiful princess. Something like that."

"I'm definitely back in my environment. It feels great."

Oakman and the Wildcats take the field February 8.

Heads up, quarterbacks.