Leinster's Stuart Lancaster is wary of overthinking the dips in form that Saracens have suffered this season, ahead of their Champions Cup quarter-final clash on Sunday (3.30pm).

The English side are the reigning champions in this competition but their current form has wavered at times, shipping consecutive defeats to Clermont Auvergne back in December.

They followed that up with a 15-15 draw against the Ospreys before scoring a big victory over Northampton Saints to narrowly secure their place in the quarter-finals against a Leinster side who earned top seeding with an eye-catching passage to the last-eight.

Additionally, the three-time European champions have the advantage of taking on the Premiership side in front of a large home support at the Aviva Stadium.

But Lancaster is giving little thought to Sarries' previous blips as they prepare for the showdown. Indeed, Leinster are no stranger to defeat and will be coming into this tie on the back of a Pro14 loss to the Ospreys last weekend.

Similar to their opponents, they'll also be looking to draw motivation from that result to achieve a better outcome on Easter Sunday. 

"I don’t think any team goes through the season unbeaten. No team," he said.

"You have dips along the way. Exeter lost two or three in the Premiership yet went on to win it. You learn a lot about yourself when you lose and sometimes it’s for the better.

"I can’t say I was pleased with losing against the Ospreys but it certainly gives us plenty of motivation going into this week."

There are doubts over the fitness of regular out-half Owen Farrell after he sustained a thigh injury in England's Six Nations defeat to Ireland, although the club are hopeful he will recover in time to be available for selection.

His absence would be a setback for Mark McCall's charges, but Lancaster knows they have reinforcements who can fill the void. Alex Lozowski deputised for Farrell in their Aviva Premiership tie against Harlequinns last Saturday, and kicked 14 points in their 24-11 victory.

"I thought Alex Lozowski did a great job at the weekend," says Lancaster. "He's involved in the England camp for a reason.

"And I think people again try and put all the attention often to one player, but it's the sum of their parts that makes Saracens effective."

Leinster are blessed with a strong cohort of players who tasted Grand Slam success on St Patrick's Day in Twickenham. Seven of the starting side that defeated England came from the Blues camp, while a further seven players were among the replacements.

"There’s be a spring in the step and the confidence that winning a Grand Slam brings, but that said, every game starts from zero"

Conversely, six of the Saracens contingent were involved overall in the fixture after England had already failed in their quest to defend their Six Nations title. 

Lancaster is happy to see Ireland's Leinster representatives coming back into camp as champions, but the club competition presents a new challenge for them all and achievements from elsewhere will have no bearing on the outcome.

"There’s be a spring in the step and the confidence that winning a Grand Slam brings, but that said, every game starts from zero, as we saw on Saturday. We had quite a few guys that played in the Grand Slam (match) and we got beaten fair and square by Ospreys.

"It works on the flip side for Saracens, too. Lads will leave a situation where they have not got the outcome they wanted, and the motivation is to go back to the club and play.

"They’re a tight-knit group at Saracens. Mark McCall has done a brilliant job at creating that sense of culture and identity that really drives their mentality.

"You saw it in Maro's [Itoje] performance on Saturday against Quins. He got Man of the Match and deservedly so. So, all this, Maro’s tired, I don’t buy it.

"He certainly didn’t play tired."