FORMER Thornbury prop Mako Vunipola was withdrawn from Saracens' 40-19 rout of Harlequins at Wembley as a precautionary measure, according to director of rugby Mark McCall.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, giving British and Irish Lions head coach Warren Gatland a scare ahead of the squad announcement for the tour to New Zealand on April 19.

The England prop is a certainty for Lions selection if fit and McCall revealed that he was taken off to avoid any risk ahead of the 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."