Dublin - Ireland's Rory Best broke his forearm in the heartbreaking last-gasp defeat by New Zealand, his province Ulster said on Monday, making the hooker a doubt for the start of the Six Nations in just over two months.
The hooker scored Ireland's second try in an opening 20-minute blitz that saw them lead the All Blacks by 19-0 but left the field soon after holding his right arm.
New Zealand came back to win 24-22 thanks to a converted try at the end.
Best was due to see a specialist in Belfast on Monday, Ulster said in a statement.
Ireland begin their Six Nations campaign against Wales on Feb. 2. Understudy hooker Richardt Strauss has been ruled out for the season after he was diagnosed with a heart condition last month.
Best is also set to miss Ulster's Heineken Cup double header with Treviso next month.