Ireland centre Garry Ringrose will miss the Guinness Six Nations matches against Wales and England after undergoing a "procedure" on a hand injury.
Ringrose sustained the problem during Saturday's 19-12 win over Scotland and was replaced at half-time.
According to the Irish Rugby Football Union, the 25-year-old will "stay connected" with Andy Farrell's squad and should be fit to face Italy in Dublin on March 7.
"Garry Ringrose has had a procedure on a hand injury and is due to be available for selection ahead of round four of the Championship," read an IRFU statement. "Garry will stay connected with the squad as a member of the leadership group."
Ireland host reigning Grand Slam champions Wales on Saturday, before travelling to Twickenham to play Eddie Jones' England on February 23.
Ringrose was replaced by Robbie Henshaw during the opening-weekend victory over the Scots, with Munster's Chris Farrell and Ulster pair Stuart McCloskey and Will Addison other options to take his place.
Meanwhile, forwards Caelan Doris and Dave Kilcoyne are undergoing return-to-play protocols after suffering head injuries against Gregor Townsend's men.
Doris' international debut at No.8 lasted less than five minutes, before Kilcoyne was forced off in the closing stages having earlier come on as a replacement for prop Cian Healy.
Prop Tadhg Furlong is being monitored after reporting tightness in a calf muscle, while Leinster back-row Will Connors, who had previously been included as a development player, has been added to head coach Farrell's main squad.
Elsewhere, former England captain Chris Robshaw has announced he is to leave Harlequins at the end of the season after 16 years with the club.
The 33-year-old flanker played 66 Tests for England, his last coming against the Springboks in June 2018.
Robshaw has made 203 appearances for Quins, captaining the side a record 92 times, and twice won the Premiership Player of the Year award during his time at the Stoop.
He is one of only two players to appear over 200 times for the club.
Robshaw said: "As a boy, wearing my oversized Harlequins shirt, I could never have imagined I would be fortunate enough to play for the team I admired the most, which is why it has been a particularly difficult decision for me to leave the club after 16 extraordinary years.
"I will be hanging up my Harlequins shirt at the end of the season. Though there is so much I will miss about playing for this team, I will always be eternally grateful and proud for having had the chance to stand alongside such extraordinary players, all the while being supported by the best fans in the world."