England prop Mako Vunipola will begin his comeback from injury when Saracens tackle Aviva Premiership opponents Gloucester on Friday.

Vunipola has been sidelined for nine weeks due to knee trouble, missing a number of domestic and European games for his club, plus England's opening RBS 6 Nations Tests against France and Wales.

But the 26-year-old, who has won 39 caps, now looks on course to be available for the latter stages of England's Six Nations campaign.

His powerful presence, both as a scrummager and around the field, could even be utilised by England boss Eddie Jones for the Twickenham appointment with struggling Italy on Sunday week.

The first priority, though, will be to emerge unscathed from Saracens' Kingsholm trip, with Vunipola among a number of changes from the side surprisingly beaten by Worcester last weekend.

Second-placed Saracens are currently five points adrift of leaders Wasps, and they will encounter a Gloucester side reeling from suffering a comprehensive defeat against Leicester five days ago.

And Gloucester rugby director David Humphreys has pulled no punches in the aftermath of that 34-9 Welford Road drubbing.

"We were disappointed, frustrated and angry that, probably for the first time this season, we turned up at a game and just didn't perform," he said.

"We didn't really fire a shot and that was the most disappointing thing.

"Our focus has been very much on making sure that the issues we had last week aren't there this week, because we know that Saracens will pose a very similar challenge to the one we faced last week with Leicester.

"Strong set-piece, physical pack - it is something we've brought every week to every game, and we've been tough to play against all season. Yes, the results haven't always gone our way, but we have been tough to play against.

"Come Friday night, we will be well-prepared and I have no doubt that the supporters will see a very big reaction from the players.

"We love playing at Kingsholm. Friday night under lights, it will be a big atmosphere, and the players are looking forward to getting back there and responding to the disappointment of last weekend."

Gloucester have claimed a solitary win from their last seven Premiership games against Saracens, but their recent record at Kingsholm is impressive, with just one loss in all competitions since early October.

Humphreys has made five changes from the Leicester match, with two switches behind the scrum as centre Matt Scott and wing David Halaifonua both start.

And in the pack, Wales back-row forward Ross Moriarty returns to action, along with prop Salesi Ma'afu and England international number eight Ben Morgan.

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