Saints duo added to England 'shadow squad'
Two more Saints players have been added to England's Six Nations 'shadow squad'.
David Ribbans and Lewis Ludlam will both be part of the back-up group, joining club-mates Alex Mitchell and George Furbank on the reserve list.
But it will not affect their roles at Saints, who they will be able to play for during the Six Nations unless promoted to England's main group.
An RFU press release, issued on Tuesday afternoon, read: "Sam Underhill has withdrawn from the England squad for the Guinness Six Nations with a hip injury.
"Wasps’ Jack Willis has been called up to Eddie Jones’ side for the tournament.
"The squad will meet at St George’s Park tomorrow (Wednesday, January 27) as they begin preparations for the tournament.
"England’s first game is against Scotland at Twickenham Stadium on Saturday, February 6 (4.45pm KO).
"Alec Hepburn, Lewis Ludlam and David Ribbans have been added to the shadow squad."
Courtney Lawes is the only member of the Northampton squad who is guaranteed to be with England for the duration of the international tournament.
Dan Biggar will play for Wales but will be able to return to feature for Saints on weekends when his country do not have a Six Nations fixture.
That means Biggar is available for selection against Gloucester this Saturday, but Lawes is not.
Ribbans, Ludlam, Mitchell and Furbank are all available for the Gallagher Premiership game at Kingsholm.
But Tom Wood is suspended and Teimana Harrison is a doubt due to injury.