Blues have been handed another injury blow ahead of the new season after it emerged that centre Liam Roberts is set to undergo a groin operation early next week.

The 25-year-old is now almost certain to miss the start of the new National League One season, but it is still unclear as to how long he will be out for.

Director of rugby Mike Rayer said he is disappointed to be without the outside centre for the big kick-off later this month, while skipper Dan Richmond also remains a doubt.

Rayer said: "Liam is going to have a small operation on his groin. It will be to repair a bit of damage that wasn't picked up by the MRI scan. We're obviously disappointed as it could keep him out for anything between two and eight weeks."

On Richmond, he added: "There is a lot of swelling and bruising around the ankle and, although he is training with us and throwing the ball around, it is difficult to estimate how long he'll be out for, as we have to wait until the swelling settles down and see how he reacts to that."

The injury to Richmond, coupled with the absence of fellow hooker Greg Sammons, who is away with parent-club Leicester Tigers, means that one of last year's U19s, Chris Locke, and prop James Graham will be given a run-out at number two during Saturday's pre-season friendly at North Walsham.

Back-rower Ben Pienaar is also away with Leicester, while scrum-half Nick Walshe will miss the game with a hamstring problem.

Meanwhile, Rayer said he is delighted to have captured young lock Phil Hoy on a season-long loan from Northampton Saints.

The 6ft 7ins second-rower also represented Ampthill at every level of rugby, from the minis up to the senior side.

On the signing, Rayer said: "The second row is an area we wanted to strengthen and he is the one we've been waiting for.

"He is an enthusiastic young player, who will want to make his mark here and develop into a future first team player at Northampton."