London - Scotland flyhalf Duncan Weir will miss the upcoming Six Nations Championship due to an arm injury, club side Glasgow announced on Monday.
The 23-year-old has undergone surgery on his right bicep and will be out of action for four months after injuring his arm in Glasgow's Celtic League clash with Scottish rivals Edinburgh on December 27.
"Following an injury sustained in the game against Edinburgh Rugby at Scotstoun on Saturday, December 27 and a subsequent MRI scan at BMI Ross Hall Hospital, it was advised that Duncan Weir required surgery to repair his right biceps," said a Glasgow statement.
"Duncan has successfully undergone surgery and will be out of action for up to four months."
Weir was Scotland's starting outside half in the 2014 Six nations and it was his last-gasp drop-goal that secured a 21-20 win away to Italy in Rome.
That victory saw the Scots finish fifth, one place above the bottom of the table Azzurri, who lost all their matches in the 2014 Six Nations.
The 18-times capped Weir also played in the Scotland side that beat Argentina 21-19 in Cordoba last June, kicking 11 points in the victory over the Pumas, before being on the losing side to South Africa.
Weir was named in coach Vern Cotter's squad for last year's November internationals but lost the No 10 shirt to Glasgow team-mate Finn Russell.
Cotter is due to announce his squad for this season's Six Nations, the New Zealander's first as Scotland coach, on Tuesday with the Scots starting the 2015 Championship away to France on February 7.