If Anderson Silva WANTS Roy Jones Jr., he's gonna GET Roy Jones Jr. -- 'cause RJJ tells TMZ he'll accept Spider's challenge to a boxing match ... but the clock's tickin'.
We spoke to the 44-year-old former boxing champ in L.A. this week ... who says he heard Silva loud and clear when Anderson told the New York Post about his dream to fight a "great champion" like Jones.
38-year-old Silva is currently under contract with the UFC ... but suggested that UFC honcho Dana White should strike a deal to make the fight happen.
As for Roy -- once considered the best pound-for-pound fighter on the planet -- he tells TMZ, "I would love it ... Call me and we'll make that happen."
But Roy is concerned about his age -- and says if the fight is gonna happen, it's gotta happen ASAP -- in fact, Jones suggested the two get in the ring right after Silva fights Chris Weidman at UFC 162 on July 6.