Vunipola: Discipline crucial for Saracens

The clubs meet at the Madejski Stadium in the first all-English quarterfinals since Wasps beat Northampton on their way to becoming European champions in 2007. 

The English champions confirmed their place in this season's Premiership play-offs with a 22-12 win over Challenge Cup semi-finalists Harlequins at Wembley at the weekend.

At the same time, Wasps ran in eight tries in a 54-35 victory at Sixways that not only moved them above Exeter Chiefs into second place, but also saw them through to the play-offs for the first time in eight years.

"We are pleased with the result, although we know there are things to clear up," said Vunipola.

"Our discipline let us down a bit against Harlequins and that starts from me at scrum time. 

"We'll go away and learn the lessons from that, but we know we will have to be a lot better when we play Wasps."

It is 1-1 between the two teams this season, with each side winning away from home.