Roy Jones Jr. says Oscar De La Hoya is kinda right ... the Mayweather vs. McGregor fight could seriously damage boxing -- if Conor wins.

Long story short, Roy says the only way Conor wins this fight is if he gets "lucky" -- otherwise, Mayweather should beat that ass.

But Roy says he fully supports the bout -- because it's entertaining and that's what the people want. 

In fact, that's why he tells us he's STILL serious about fighting Anderson Silva -- if Dana White gives him the green light.