Glasgow Warriors will be without one of their most consistent performers for up to eight weeks.
In-form prop Moray Low will have knee surgery and is not expected to return to action until the end of April.
The 25-year-old suffered the injury in last weekend’s Magners League defeat to Cardiff Blues at Firhill and underwent a scan to assess the damage on Wednesday night.
"The scan has showed damage to Moray’s right knee,” said Scotland team doctor James Robson.
"He will now be under the care of specialist orthopaedic surgeon Graham Lawson at Spire Murrayfield Hospital and will have to undergo keyhole surgery.
"Typical recovery from such a procedure can take up to eight weeks and on behalf of the Scotland squad we would wish Moray a speedy return to the game."
The setback means Low will miss the remainder of Scotland’s Six Nations campaign, as well a large chunk of the Magners League season.
The Warriors currently sit in second-place in the Magners League table after defeat to the Blues saw the Ospreys rob them of top spot.
An eight-week absence would see Low ruled out of Glasgow’s domestic clashes with Connacht, Munster, the Dragons, Ulster and the home and away ties with Leinster.
There would then be just one match of the regular season remaining before the Play Off semi-finals – the trip to the Scarlets on the weekend of May 7.