Conor's Ex-Sparring Partner Willing To Train Again Under 1 Condition

Conor McGregor's former sparring partner says he's down to put their beef aside and train the UFC superstar ... but there's a catch.

Chris van Heerden -- former IBO welterweight champ -- and McGregor sparred in May 2016, but parted ways after video surfaced of them training.

Conor's most recent partner, Paulie Malignaggi, quit Thursday under similar circumstances ... when photos leaked appearing to show P.M. getting knocked to the canvas.

CVH says he talked to Malignaggi Thursday night about what really went down ... and understands why he wants the full sparring video released.

Van Heerden says he's willing to let his grudge go and step back inside the squared circle with the Notorious ... but it's gonna cost him some of that fat $100 million paycheck.