Hamm and Bell are slated to fight on the Misfits Boxing card on May 25 at the NRG Arena in Houston, Texas ... and Tristan says he's ready for the challenge ahead, despite his debut being just six months ago against Rodney Petersen (you may know him from his run-in with Nate Diaz).

Hamm knocked that dude out in just 53 seconds ... and he's now looking for a similar outcome against Bell.

"I definitely think there's a knockout opportunity," Hamm said about the upcoming bout.

"He's only had a number of fights, he's been around for a while, he's been training for a while but he only has a few fights."

Once he's done with the former Pittsburgh Steelers running back, Hamm told us he's targeting either Danis or the guy the MMA fighter couldn't beat -- WWE Superstar Logan Paul.

"If Logan wants to run it, that'd be fire," Hamm said. "[But] fighting Dillon Danis, I think that's still a very entertaining fight."

Of course, some fans aren't taking Hamm or any of the influencer-turned-boxers seriously ... but Tristan says they should -- 'cause it's man versus man at the end of the day.

Hamm, who also creates fitness programs, has taken all the appropriate steps to become a pro boxer ... including putting together a strong team with Jake Paul's former coach BJ Flores, boxing instructor Pedro Diaz, and sparring partner, boxing champ Noel Mikaelian.

Hamm also said he spars with his girlfriend, 4-1 boxer Stefi Cohen ... which you may be aware of, as footage of their training has gone viral.