Coach: McGregor suffered past knee injury training with Rory MacDonald
They say "iron sharpens iron," but living by that adage can be dangerous for some of the UFC's best fighters.
It's not uncommon for stars like Conor McGregor to bring in other high-profile names to train with them, or to visit different camps in preparation for a bout.
In a recently released autobiography entitled "Win or Learn," McGregor's coach John Kavanagh reveals how an intense training session with No. 1-ranked welterweight Rory MacDonald almost resulted in McGregor being pulled from UFC 189 last July.
McGregor just so happened to be booked for a world championship fight on that card.
"Artem explained that Conor and Rory MacDonald - a Canadian welterweight who was scheduled to take on the (welterweight) champion, Robbie Lawler, in UFC 189 - had been training together that afternoon," Kavanagh wrote, according to Irish news site The42.
"Nothing strenuous, just a bit of grappling. But during their session, Rory landed awkwardly on Conor's left knee - the same knee he had injured against Max Holloway."
McGregor's first knee injury took him out of action for almost a year and Kavanagh didn't want to take any chances with the second one. But McGregor insisted on fighting through it.
"I still wanted Conor to have a scan," Kavanagh wrote. "If we needed to push the fight back a few months, so be it. But he was adamant. There was no telling him otherwise. All I could do was take his word for it and devote myself to the task of preparing him accordingly."
The gamble paid off. McGregor went on to knock out replacement opponent Chad Mendes for the UFC interim featherweight title and then do the same to Jose Aldo in December to become the undisputed champion.
- With h/t to FOX Sports