Mako Vunipola's injury isn't serious, says Mark McCall

Mako Vunipola was withdrawn from Saracens' 40-19 rout of Harlequins at Wembley as a precautionary measure, according to director of rugby Mark McCall.

Vunipola lasted only four minutes into the second half before being replaced because of a knee injury.

The prop missed the start of this year's Six Nations with a knee problem and the sight of him leaving the field may also have concerned British & Irish Lions head coach Warren Gatland as well as McCall.

Gatland is due to announce his squad for the British & Irish Lions tour to New Zealand on April 19 and if fit England's prop is likely to be in contention for a spot on the plane.

To the relief of both coaches, McCall revealed after the game that Vunipola was taken off to avoid any undue risk ahead of their Champions Cup semi-final against Munster in Dublin in a fortnight.

"Mako took a little bang to his knee just before half-time and felt a little bit uncomfortable," McCall said.

"We don't think it's anything serious at all, but we just wanted to be sensible with the big game coming up in two weeks' time."

Chris Ashton, Schalk Brits, Michael Rhodes and Alex Goode crossed to secure the bonus-point win that guarantees Saracens an eighth successive appearance in the Aviva Premiership play-offs.

The double winners are now positioned only one point adrift of second-placed Exeter and after thumping victories over Bath, Glasgow and Harlequins, they are generating momentum at the decisive phase of the season.

"This was a hugely pleasing performance because we're going big game after big game after big game," said McCall.

"Sunday's game against Glasgow was big for us, so to show the qualities that we did was superb, although not everything we did was perfect.

"The effort we put in - we had a huge defensive effort especially in the second half. I thought the players were magnificent.

"The first seven months of the season are about getting into strong positions in the competition we're interested in and now there are a lot of things to be excited about."

Harlequins' ambitions of finishing in the top four were dealt a blow with three matches remaining and director of rugby John Kingston could only admire the reigning champions' performance.

"Once Saracens get ahead on the scoreboard it becomes very difficult and they're very good at taking advantages of your mistakes. They deserved it," Kingston said.

"They're difficult to break down and they take the laws to the limit, but they're an incredibly physical side and we ran into a brick wall. They're a great side at the moment."