France's Romain Poite will be in charge of the first Heineken Cup quarter-final to be staged at Twickenham Stadium when Saracens clash with last season's defeated finalists, Ulster Rugby, also on Saturday, 6 April, while the Anglo-Irish confrontation of the pool-stage top seeds, Harlequins, and two-time tournament winners, Munster Rugby, at the Twickenham Stoop the following day will be refereed by Poite's compatriot, Jérôme Garces.
George Clancy of Ireland will be in the middle for the last of the quarter-finals when Toulon take on two-time champions, Leicester Tigers, in one of the biggest matches ever played at the historic Stade Félix Mayol on Sunday, 7 April.
The Heineken Cup referee and assistant referee appointments were announced following a meeting of the ERC Match Officials sub-committee. The meeting reviewed match official performances across all relevant tournaments in conjunction with feedback from the referee managers in each Union and from club coaching staff.
"We will be asking the match officials to continue to focus on key areas of the game in order to allow a contest for the ball by both teams and to give the ball-carrying team the space to play within the laws," said ERC Match Official Performance Manager, Donal Courtney.
"The officials will be reminded to effectively manage all aspects of the scrum, as well as tackle and ruck situations, in particular where players wilfully go off their feet to prevent a fair contest for the ball. They will also be asked to be strict on issues of foul play, especially dangerous tackles, and to be vigilant for lineout maul obstruction and for players going offside from kicks," added Courtney.
As the tournament intensifies for the knockout stage, the assistant referees for the four quarter-finals have been appointed on the basis of their experience, whereas for the pool stage, assistant referees were nominated by the Unions of the match referees.
Heineken Cup quarter-finals
(kick-offs local time)
Saturday, 6 April
ASM Clermont Auvergne v Montpellier, Stade Marcel Michelin (16.40)
Referee: Wayne Barnes (Eng); Assistant referee 1: JP Doyle (Eng); Assistant referee 2: Stuart Terheege (Eng)
Saracens v Ulster Rugby, Twickenham Stadium (18.30)
Referee: Romain Poite (Fra); Assistant referee 1: Leighton Hodges (Wal); Assistant referee 2: Cedric Marchat (Fra)
Sunday, 7 April
Harlequins v Munster Rugby, Twickenham Stoop (14.00)
Referee: Jerôme Garces (Fra); Assistant referee 1: Neil Paterson (Sco); Assistant referee 2: Laurent Cardona (Fra)
Toulon v Leicester Tigers, Stade Félix Mayol (17.30)
Referee : George Clancy (Ire); Assistant referee 1: Peter Fitzgibbon (Ire); Assistant referee 2: Leo Colgan (Ire)