Brian O’Driscoll suffered concussion following his tackle on All Black secondrow Brodie Retallick in Sunday’s Autumn International at the Aviva Stadium.
His recovery will adhere to the established return to play protocols, whereby he will be monitored for six days by Leinster medical staff.
Theoretically, O'Driscoll could play at the weekend for his province but players centrally involved in the three November Test matches will rest this week anyway.
Fractured
It has been confirmed hooker Rory Best fractured his right forearm in the game and went to see a specialist in Belfast yesterday. He could miss Ireland's opening matches of the 2014 Six Nations Championship.
Paul O’Connell was out out for over three months after fracturing a forearm in the first Lions Test against the Wallabies on June 22nd and returned, with Munster, on September 28th.
Ireland open the Six Nations Championship against Scotland on Sunday, February 2nd, with Wales following on February 8th.
Johnny Sexton, who tightened up in the second half of Sunday's match, was also due to have a scan on his hamstring.
Ulster have a list of injury concerns. Loose forward Iain Henderson suffered a hamstring injury in the win over Edinburgh on Friday and had an MRI scan yesterday.
Secondrow Lewis Stevenson sustained medial ligament damage in his right knee and will be out for up to six weeks, while Michael Allen, like O'Driscoll, suffered concussion and will follow the normal return-to-play protocols.
Calf injury
Number eight Nick Williams' calf injury will keep him out for between four and six weeks
There was better news from Munster, with Keith Earls (knee), Ian Keatley (hip/groin) and Luke O’Dea (hamstring) all returning to full training this week, while Tommy O’Donnell has signed a two-year contract extension with Munster Rugby and the IRFU that will come into effect from July 2014.
The flanker’s form last season was rewarded when he won the first of two Ireland caps on the tour of North America. He was also Munster’s player of the year.
O’Donnell has been out of action since September after injuring his knee against Zebre but head coach Rob Penney revealed last week the player should be back to full training in December.
Alex Cuthbert could return to the Wales team for next Saturday's autumn series finale against Australia. He suffered an ankle injury on Heineken Cup duty for Cardiff Blues last month.
