by TMZ Sports

One of Floyd Mayweather's TMT members tells TMZ Sports ... he's courting Nate Diaz to walk out with Floyd for the Conor McGregor fight -- and says there's a REAL chance it will happen.

Mayweather faces McGregor on August 26th at the T-Mobile Arena in Las Vegas - where McGregor defeated Diaz by decision last August. Diaz won the first bout last March by submission in round two.

The man with the plan to get Diaz is "Love & Hip Hop" star, Jason Lee -- who's so close with Floyd, he was part of the boxer's entourage during the McGregor news conference in London.

Lee also happens to be from Stockton, CA -- home of Nate Diaz -- and says he's making a serious run to get Nate to be a special TMT VIP for the fight ... to essentially troll Conor.

We also asked Lee if Justin Bieber would be in Floyd's corner for the fight -- since he has been in the past -- but it sounds like JB is taking some time away from TMT to focus on Jesus.

Live event tickets for the Floyd Mayweather vs. Conor McGregor showdown will go on sale to the general public later today at 10 a.m. PT through Ticketmaster for the Saturday, Aug. 26 event taking place at T-Mobile Arena in Las Vegas. All guests will receive a 3-D ticket as a commemorative souvenir to bring home from this once-in-a-lifetime event.

The official on-sale went live yesterday, powered by Ticketmaster Verified Fan®. For those who weren't able to preregister for the Verified Fan® on-sale, additional tickets will be available for purchase on Ticketmaster.com starting tomorrow, Wednesday, July 26 at 10 a.m. PT.