Ireland are likely to be without flanker Stephen Ferris for their entire autumn international campaign.
The back-rower suffered an ankle injury playing for Ulster against Edinburgh in the RaboDirect PRO12 on Friday night and is expected to be out of action for around a month.
Ferris twisted his right leg awkwardly when he was tackled after making one of his trademark surging charges, going down in agony for the second time in the game.
The 27-year-old was playing for the first time in a month after spending four matches on the sidelines with a back problem.
Ulster head coach Mark Anscombe said in the aftermath of the 45-20 win at Ravenhill that Ferris' ankle had swollen up badly, and his absence adds to a long list of players unavailable to Ireland coach Declan Kidney.
Kidney is already without the likes of Rory Best and Brian O'Driscoll for the whole of November, which sees them take on South Africa on Saturday and Argentina two weeks later.
An Irish XV also faces Fiji at Thomond Park between those two Aviva Stadium internationals.