Daniel Dubois refused to be drawn into a conversation over a sparring session with Anthony Joshua seven years ago.
Joshua said that Dubois had indeed “cracked” him in the past, but did not score a knockout.
Sparring sessions between fighters are generally kept under wraps unless one man wants to score points, particularly in the run-up to an official bout.
The two heavyweights now go head-to-head on September 21, as they contest the IBF strap.
Speaking to Sky Sports, Dubois looked to keep the relations civil and made no claims over the past.
He said: "I don't want to talk about no sparring or none of that. It happened seven years ago, and to be honest, I can't remember that.
"I'm not here to spar him, I'm here to fight him. So let's keep it on the fight.
"What I will say is that it was great being up there and sharing that experience with these guys that were at the top of their game.
"Another thing, speaking of sparring, people have mentioned sparring me and they've come unstuck, so I don't want any bad luck to follow me!"
Live on DAZN: Check your region for PFL and PFL Europe on DAZN . Click here for details.