Pat Lam and Joe Schmidt will wait anxiously for the findings of a scan on Ultan Dillane's ankle.
The Ireland second row had not long entered into the Inter-provincial derby in Ulster when forced to leave last Friday night.
Whatever about starting in the Six Nations, Dillane offers explosive, X-Factor impact off the bench.
For Connacht, their injury crisis lurches from bad to worse as tight-prop prop Finlay Bealham, another in Schmidt's plans, is following return-to-play protocols from concussion.
Second choice tight-head Conor Carey is out for three months with a foot injury; third-choice Ronan Loughney for six weeks with a knee injury.
In the front row, Dominic Robertson-McCoy is in the midst of rehabilitating his shoulder and Clontarf's AIL winner Ivan Soroka's foot will be ready by mid-February.
This is just the beginning of a sad and sorry trail of injuries that mean Connacht's Champions Cup ambitions and even a Top-6 finish in the PRO12 are being seriously compromised.
In the centre, Bundee Aki (ankle) won't be back until mid-February, Craig Ronaldson (thigh) until mid-January, Eoin Griffin (chest) until March.
Peter Robb (thigh) will return to training this week; Stacey Ili (ankle) to running.
Jack Carty will carry the weight of responsibility for the number ten shirt.
Marnitz Boshoff's shoulder surgery rules him out for three months and Shane O'Leary is still recovering from concussion.
Lock Andrew Browne is due to return from an ankle in February. Back row Eoghan Masterson's knee is still a few weeks away.
There is encouraging news concerning a thigh injury to captain John Muldoon.
The number eight has not been ruled out for the Munster match on Saturday, although he is far from certain to play.
Former New Zealand U20 captain Jake Heenan is also a possible to be involved from knee and ankle injuries.