Wales are sweating on an injury to fly-half star Dan Biggar just a fortnight before their opening NatWest 6 Nations game against Scotland.
And it comes barely 24 hours after his fellow Wales number 10 Rhys Priestland was sidelined for the majority of the tournament due to a hamstring problem.
Biggar left the pitch at Stade Marcel-Michelin with his right shoulder in a shirt-sling six minutes from the end of Ospreys' 24-7 European Champions Cup defeat against Clermont Auvergne.
Playmaker Biggar, who has won 60 Wales caps and toured New Zealand with the British and Irish Lions last summer, described his injury as "not too bad" shortly after going off.
He was on the receiving end of a powerful challenge from Clermont number eight Fritz Lee.
Ospreys head coach Steve Tandy, meanwhile, would only say "Dan's with the medics," although early indications appeared to suggest no structural damage to Biggar's shoulder.
A bad night for the Ospreys and a potentially devastating one for Wales too https://t.co/3mAwMfFNNW— WalesOnline Rugby (@WalesRugby) January 20, 2018
It is, though, the last thing Wales head coach Warren Gatland needs after naming a 39-man Six Nations squad earlier this week.
With the experienced Priestland gone, he cannot afford to lose first-choice Biggar as well. Wales' first three Six Nations games are against Scotland, England and Ireland.
Gatland does have other options in terms of the number 10 shirt, but they are inexperienced ones, facing an apparent choice between Gloucester's Owen Williams, Scarlets back Rhys Patchell and Cardiff Blues' Gareth Anscombe, should Biggar be ruled out.
Biggar is set to join up with the Wales squad on Monday, when further checks and tests can expect to be carried out.
Gatland has already lost injured Lions Sam Warburton and Jonathan Davies from the entire Six Nations, while number eight Taulupe Faletau is set to miss the first three matches as he recovers from a knee injury and lock Jake Ball remains absent due to a dislocated shoulder.
Wing Liam Williams, meanwhile, missed Saracens' Champions Cup clash against Northampton on Saturday due to what his club described as "a knock".