Ireland's Farrell set to miss rest of Six Nations
The IRFU said Farrell received treatment on the pitch after twisting his knee in the turf but rejoined the session, feeling well.
The statement added: "He was sent for a precautionary scan this afternoon which indicated some ligament damage had occurred and he will now see a specialist. Chris is unlikely to be available for the remainder of the Six Nations."
Munster star Farrell, 24, won the man-of-the-match award in Ireland's 37-27 win over Wales in Dublin on Saturday, his Six Nations debut.
Ireland are already without long-term absentees Jared Payne and Robbie Henshaw, who were, for a while, the first-choice pairing at centre, while Garry Ringrose is still seeking full match sharpness after ankle trouble.
Joe Schmidt's team, top of the Six Nations table with three wins out of three, are bidding for their first Grand Slam in nine years.
Ireland face Scotland in Dublin on March 10, where victory would set them up for a tilt at only the third Grand Slam in their history when they play England at Twickenham on March 17.
Agence France-Presse
