Ulster face an anxious wait for news on Iain Henderson's knee injury after the province's skipper limped out of Ireland's win over Scotland in the Aviva Stadium on Saturday afternoon.
The 28-year-old started the game alongside James Ryan in the second-row but left the action shortly before half-time and was replaced by Quinn Roux.
"Hendy will be going for a scan tomorrow (Sunday)," said the Irish head coach Andy Farrell. "He had a knee injury but obviously it's hard to assess straight after a game. He'll be off for a scan in the morning and we'll know more then.
"We had a couple of HIAs, James Ryan came off for a HIA and obviously Pete (O'Mahony) came off but went back on. So not too bad. Johnny had the dead leg so we'll see how Hendy is tomorrow."
Ulster face Toulouse at Kingspan Stadium on Friday as their Champions Cup campaign kicks off with Dan McFarland already sure to be without Henderson's fellow lock Kieran Treadwell.
Ireland won the game 31-16 to finish third in the Autumn Nations Cup with Ulster prop Eric O'Sullivan making his debut from the bench.