MMA legend Quinton 'Rampage' Jackson has issued a firm warning to Shannon Briggs.

The two athletes have been involved in a war of words in recent weeks.

Briggs, a former WBO heavyweight champion, wants to fight Jackson in a boxing match and has even mentioned the idea of facing him under MMA rules.

The 43-year-old Jackson has been away from the cage since December 2019, when he was knocked out in one round by Fedor Emelianenko. Jackson, who never boxed, has lost three of last four outings in MMA.

Briggs has been away from the ring for a long time. The 49-year-old boxer, who never officially retired, has been inactive since May of 2016, when he knocked out Emilio Zarate in one round.

In 2017, Briggs was scheduled to face Fres Oquendo - but their fight was canceled when Briggs tested positive for a banned substance.

Jackson believes Briggs, based on his age and inactivity, would get punished if they met in the ring.

"From what I know, Shannon hasn't fought over five years," Jackson told the DAZN Boxing Show. "He smokes a lot of cannabis. He call it Shannon-buss. He just old. He got one foot in in a nursing home. He shouldn't be calling me out. 

"I'm older too. But he older than me. My last fight was New Year's 2020 even though you can't really call it a fight because I got my ass knocked out within like first two minutes or so. But I still was in training camp.

"We gonna get in there. I gotta shut his old ass up."