Ireland fly-half Paddy Jackson could miss the Six Nations due to a dislocated elbow.
The 23-year-old suffered the problem on Sunday during club Ulster's 60-22 defeat to Toulon in the European Rugby Champions Cup.
It is currently unclear how long Jackson will remain sidelined for, but his participation in the upcoming tournament has been thrown into doubt.
Ireland start their Six Nations campaign away to Italy on February 7.
Jackson has won nine caps for his country following his debut back in 2013.