Things kicked off when 'The Mauler' said Jones wasn't a 'good person' or a true champion after his brutal TKO victory over Glover Teixeira at UFC Stockholm last month.
'Bones', who beat Gustafsson via decision in a five-round championship epic at UFC 165, fired back by calling Gustafsson a 'dork' with no 'heart'.
Things continued to escalate from there, and Gustafsson insinuated that Jones only won at UFC 165 because of the lack of USADA drug testing at the time.
Speaking to Ariel Helwani on Monday's edition of The MMA Hour, the top-ranked Gustafsson stood by his comments and said Jones has probably been using performance enhancing drugs for a long time.
"I believe so, I believe so,” Gustafsson said when asked if he thought Jones was using PEDs in their 2013 championship bout (h/t Chuck Mindenhall of MMA Fighting). “I think he’s been doing a lot of stuff that he shouldn’t be doing. It’s tragic to say, but I believe he’s been doing sh*t he shouldn’t for a long time.”
Jones, who is currently serving a one-year suspension for his failed drug test at UFC 200, was forced to relinquish the light heavyweight title after a hit-and-run incident in 2015. During his time off, the former champion became obsessed with bodybuilding and bulked up for his return fight against Ovince Saint Preux at UFC 197.
Gustafsson isn't sure whether Jones was taking PEDs to prepare for OSP but believes he used them in the past.
“Well, you know, he hadn’t been in the cage for a long time when he fought him,” he said. “I don’t know. I don’t know if he was on it or not for that fight, but I believe he was when we fought and stuff like that. But anyway, it’s history now and new times are coming, and we probably will fight again some day.”
Gustafsson, who is ranked as the No. 1 LHW contender in the world, is likely to face the winner in the fall or face the No. 2 ranked Jimi Manuwa in a top contenders bout.