It is safe to say that Sam Allardyce and Rafa Benitez aren't the best of pals.
And the upcoming Tyne-Wear derby at St James's Park is set to have a bit of extra spice on the touchline after the Spaniard was named the new Newcastle United manager.
Steve McClaren was axed as head coach on Friday lunchtime, with former Liverpool, Chelsea and Real Madrid manager Benitez taking charge on an initial three-year deal.
But Sunderland boss Allardyce has a long-running feud with Benitez dating back mainly to his time in charge at Bolton and Blackburn, which coincided with the Spaniard’s stint at Liverpool from 2004-10.
Their feud was reignited when Benitez hit back at Allardyce claims that he had nothing to do with Liverpool’s 2005 Champions League success.
Benitez oversaw a stunning Champions League victory at Liverpool, with his side recovering from 3-0 down against AC Milan in the final in Istanbul.
But Allardyce, in his autobiography 'Big Sam', wrote: "Rafa Benitez was another one. When we beat him he would complain, 'They don't play my type of football.'
"What was that then? Winning football? He didn't like me and he thought he was superior. Here was a trendy foreign manager with all his smart ideas getting beat by some oik from the Midlands.
"Benitez wouldn't talk to me at all and that just made it all the better when we won. I can't stand people who disrespect me the way he did.
"I didn't create any of the conflict between us, it was all down to him.
“Of course he can say he won the Champions League with Liverpool, which is something I never did. But it was nowt to do with him.
“I don’t blame Benitez for claiming credit but as managers we know the truth. It’s like when you make a substitution in desperation and it comes off.
"You get all the credit for your tactical brilliance when often it's just luck.”
Benitez - who was managing Real Madrid when the book was released - dismissed this remark, saying: "Do you know who Sam Allardyce is?
"Do you know how many trophies he has won? Well that’s my answer. It is what happens when someone has a book to sell.
"His opinion does not have a lot of value."