Mark McCall insists Saracens will embrace the toughest assignment in European rugby when they face Leinster in the quarter-finals of the Champions Cup.

A last-four appointment with the Scarlets is the prize on offer at a sold out Aviva Stadium on Easter Sunday, but it is the holders who start as underdogs when their pursuit of a hat-trick of titles resumes.

Twelve months ago Dublin was the setting for a thumping semi-final win over Munster but McCall knows a Leinster team packed full of in-form Ireland internationals are a different proposition.

"They are the top seeds, were unbeaten in their pool and they've just come off a Grand Slam, so I would say they're hot favourites for this game and maybe beyond," the Saracens director of rugby said.

"They're a high-class team, they've got players who are confident at the moment given what they did with Ireland. Around 16 of the Irish 23 are from Leinster, and they are at home.

"But we'll give it a shot. Playing away from home - we won't have any fears about that at all. Our players relish these occasions and it's going to be an unbelievable occasion.

"There's going to be 50,000 fans. That's something to look forward to and our players won't be afraid of that.

"We've won quite a few of the play-off games we've had over the last two or three seasons and that gives the players confidence.

"Some of our better performances have been in these games away from home," added McCall, who has been touted as a future Ireland coach.

Saracens' chances of causing an upset have improved with the news that Owen Farrell has recovered from a quad injury to start at fly-half, but talisman number eight Billy Vunipola is still absent with a broken arm.

Leinster are missing Sean O'Brien because of a shoulder problem, resulting in Australia forward Scott Fardy switching from second row to blindside flanker.

"You think of the quality Saracens have and their record in the last couple of seasons, they're the team we're all trying to chase and aspiring to get to that level," Leinster assistant coach Leo Cullen said.

"There's been a huge amount of working going on here in the last couple of seasons to get us to a situation where we're in a game against Saracens."

The final day of the quarter-final weekend is launched by Clermont's home clash with Top 14 rivals Racing 92. 

Follow our live blog of Leinster v Saracens (3.30pm kick-off) this afternoon on RTÉ Online and the RTÉ News Now App.