Chris Boyd has revealed that Piers Francis will not undergo surgery on his dislocated shoulder.
And the Saints boss expects the England centre to be sidelined for 'between six and eight weeks'.
But there is better news on lock Dom Barrow, centre Nafi Tuitavake and wing Ken Pisi.
Barrow has only been able to make five appearances since joining Saints last summer, with concussion and hamstring problems hampering the second row forward.
Pisi has not played since the win against Harlequins on September 7 due to a shoulder injury.
Utility back Tuitavake, who has been nursing a neck injury, has made just one appearance this season, starting in the opening-day defeat at Gloucester.
But Boyd said: "I think Ken Pisi and Nafi Tuitavake will both be available for selection next week (at home to Timisoara Saracens).
"Dom Barrow is not far away.
"Dom came back from a head knock and then tore a hamstring at training so he's had a wretched run with injuries.
"He will probably be available over the next two or three weeks so I think you'll find him running out for us in the next block of games."
And on Francis, who was forced off early on against Exeter Chiefs in the final game of 2018, Boyd said: "Piers and the medical people have chosen not to go ahead with surgery so they're going to manage that conservatively.
"His expected return to play is somewhere between six and eight weeks."
James Haskell (ankle) is expected back in the next couple of weeks, but Dylan Hartley remains a doubt for Saturday's Challenge Cup clash with Clermont Auvergne due to a 'grumbly' knee.
Harry Mallinder, Mike Haywood and Andy Symons will not play again this season.
"Harry, Mike and Andy Symons - all of whom had ACL ruptures - will not feature this year so they are all next season's prospect," Boyd confirmed.