HOOKER Niall Annett and fly-half Ryan Lamb face lengthy spells on the sidelines after becoming Worcester Warriors’ latest injury victims.

Belfast-born Annett (ankle) could be out of action for around 10 weeks after being hurt in Warriors’ 18-17 Aviva Premiership defeat to Northampton Saints last Friday.

Lamb (neck) has had an operation and the 30-year-old could be missing for 12 weeks.

Fellow fly-half Tom Heathcote (concussion) will be out for about a month.

With hooker Jaba Bregvadze on international duty with Georgia, rookie Jack Singleton is poised to start in Warriors’ front row for their Premiership clash at fifth-placed Exeter Chiefs on Saturday (4.30pm).

Singleton made his Premiership bow against Saints after coming on for the final 21 minutes and has also appeared in four other first-team matches this term.

It will be a stern test for the England under 20s starlet as Warriors chase a first Premiership victory over Exeter at the ninth attempt.

“Ryan will be out for 10 to 12 weeks with a neck injury,” explained Warriors head coach Carl Hogg. “He’s had a surgical procedure on a nerve issue in his neck.

“Tommy has had consecutive concussions so he’s going to need a stand-down period of probably about a month.

“Niall has picked up an ankle injury (syndesmosis) and will be out for a significant period of time — probably around a 10-week period.

“It’s the same type of injury which Tiff Eden and Ben Howard suffered. But we’ve got Jack who will get a start tomorrow. He did extremely well last Friday and that’s one of the things we have to bear in mind.

“The match against Northampton was very frustrating but, if you look at the integration of Jack and Andrew Kitchener, it bodes well for the long-term future of Warriors.”

Warriors sit second from bottom in the Premiership and will also be without suspended centre Ryan Mills and wing Cooper Vuna, who has been called up for Tonga, at Sandy Park.

Centre Ben Te’o is on the bench for England against Argentina tomorrow but newly-wed centre Jackson Willison has returned to Sixways after missing the Saints defeat.

“Jackson came back today and we will see what sort of health he’s in and will make an assessment tomorrow morning,” said Hogg.

“Cooper came back last weekend and has been called into the Tonga squad against Italy. For us, it’s a double-edged sword.

“We’re delighted Cooper is playing international rugby against Italy but it also means we’re another man down.

“It was a bit of a surprise for Cooper to be involved with Tonga because we only had confirmation on Sunday night but that’s part and parcel of having top-quality players at the club.”

Bryce Heem marked his long-awaited comeback after a knee injury with a try against Saints and has overcome an ankle problem sustained in the match.

Fellow wing Tom Biggs and versatile back Howard both featured for Worcester Cavaliers in their friendly win at Oxford University on Monday.

Hogg added: “With Ryan (Lamb) injured, Ryan (Mills) cited and Tommy out with concussion, it certainly leaves opportunities for people.

“We have a number who haven’t played regularly over the last six or seven weeks but can step up to the mark.”