TMZ Sports talked to 37-year-old Wonderboy -- who was recently floated as a possible opponent for 26-year-old Chimaev -- and Thompson made it crystal clear Khamzat simply doesn't deserve all the praise ... at least not yet.

"There's a lot of hype around [Khamzat] at this point. He's won three fights, he's had one fight at welterweight, he's ranked #15 right now, he's gonna be fighting a guy who ranked higher than me."

FYI, Chimaev -- who has been hit a grand total of 3 TIMES in his 3 UFC fights -- is fighting #3 ranked Leon Edwards (the fight was scheduled for this weekend, but Edwards got COVID, so it's being rescheduled.)

Thompson -- the #5 ranked welterweight -- continued ... "It's definitely a big jump for him and a test for Khamzat. So, at this point, I'm not really sold yet. I just haven't seen enough and on paper. Leon Edwards wins this all day, so I'm going for my man Edwards."

Edwards is 18-3 and has won 8 fights in a row ... with dubs over guys like Rafael dos Anjos and Donald "Cowboy" Cerrone. But Thompson says if Chimaev can take LE out ... then it'll make him a believer.

"[Khamzat] may go out there and prove us all wrong, ya never know. He'll be the real deal. I will say he's the real deal if he goes out there and just does work, but at this point, I haven't seen enough."

Speaking of big time fights, Thompson has a scrap Saturday night in Vegas against 30-year-old striker, Geoff Neal -- aka "Handz of Steel" -- who's 5-0 since signing with the UFC.