Ulster flanker Stephen Ferris will put his friendship with Leinster counterpart Sean O'Brien on the backburner as they prepare to face off in a mouthwatering back-row confrontation at the Heineken Cup final.
The Ireland internationals have become firm friends since the latter made the step up to Test level in 2009.
The duo room together when in camp with Ireland, including throughout last year's World Cup in New Zealand, but their clash as part of two outstanding back-rows is likely to have a big say in who wins the first all-Irish European final at Twickenham.
Ferris, 26, and O'Brien, 25, are among the strongest ball-carriers in the game, and their wrecking ball-like ability to bust tackles and get over the gain line will be crucial to their respective teams.
With Ferris having Pedrie Wannenburg and Chris Henry for company in the Ulster back-row, and Kevin McLaughlin and Jamie Heaslip lining up in blue with O'Brien, the stage is set for a fascinating back-row battle.
And 2009 Lions' tourist Ferris knows just how dangerous an opponent his mate O'Brien is.
Ferris said: "Sean was the European Player of the Year last season and he was unbelievable.
"We roomed together at the Rugby World Cup and he is a good mate.
"He is a great player, he is one of the best back-rowers in the world an and he has shown he is one of the best ball carriers in the northern hemisphere and we know what a threat he is.
"We haven't played against each other very much, we have been more used to playing with each other for Ireland, although we have come up against each other in training a few times.
"Obviously come Saturday we are both going to be desperate to win for our provinces.
"We will be doing our best to win the trophy but I am sure there will be a handshake between us whoever wins."
Leinster are the favourites to secure their third European crown at the home of English rugby, and in doing so become the first side to retain the Heineken Cup in its 17-year history.
For underdogs Ulster, victory would bring a second triumph after their 1999 success, and hand coach Brian McLaughlin a fairytale ending to his final match in charge.
When McLaughlin took over in July 2009 Ulster were ranked a clear third among the Irish provincial litter, with Leinster and Munster perennial challengers at Celtic and European level.
But his addition of experienced South Africans Ruan Pienaar, Wannenburg and Johann Muller to local talents such as Ferris and Andrew Trimble has reaped big dividends.
Last season's quarter-final appearance was a first since the 1999 triumph, and this term's last-eight win over Munster at Thomond Park made them just the second side to beat the two-time champions on their home patch in the Heineken Cup.
But McLaughlin's reward for guiding Ulster back to the top of the European game will be a role as the province's academy boss, with Kiwi Mark Anscombe set to take over as head coach.
While the move appears a puzzling one from the outside, Ferris is quick to laud the impact McLaughlin has made on Ulster rugby.
He said: "Brian is a great guy. He came in when things weren't brilliant and he laid down some very strong foundations.
"He made sure he brought in the calibre of player who would help, he had a plan and everyone bought into it.
"It's a shame he is moving on but he has laid a lot of foundations that will stand Ulster rugby in good stead."