We broke the story ... 41-year-old Odom and 33-year-old Carter are boxing June 12 at the Showboat Casino in Atlantic City -- all part of a big Celebrity Boxing card.

During the convo, we hit on everything from the huge height difference (Odom's 6’10, Carter's 5’11”-ish), the pressure to represent for NBA players after Nate Robinson was KO'd by Jake Paul, and whether the fight is actually real.

Some highlights:

Lamar says although he doesn’t officially have any fights on his record ... that doesn’t mean he isn’t experienced in the ring.

“I’ve always boxed, in my best years with the Lakers, I used boxing for training, and so for me to go and show what I've learned on my man's face, this is like retribution for Nate Robinson. This is gonna be easy work.”

We asked Aaron if he could realistically beat Lamar ... a giant, elite athlete who played 14 seasons in the NBA.

Without hesitation, Carter basically said ... hell yes.

“I know I can [beat Lamar]. Come June 12th, like I said, like Apollo Creed said, ‘I’m gonna drop him like a bad habit,’ and I mean that.”

Lamar ... well, he doesn’t see it goin' down that way.

“I’m pretty good, bro. It’ll be fun. But, you’ll have fun getting knocked out.”

Carter’s response??

“You will not knock me out! You will not knock me out!”

If all the trash talk didn’t convince you, Aaron made it known this is very much a real fight -- and he’s looking to do real damage.

“I want to make something very clear too, just so everybody knows. There was no secret meetings, nothing gets staged. This is as real as it gets.”

But, don't expect the beef to carry over outside of the ring, after the fight ... 'cause Lamar says there won’t be any hard feelings. In fact, he wants to chill and party with the pop star in AC.

“I’m gonna be real with you, dinners on me cause I don't want you to take this ass whoopin' personal."