The openside has been one of Scotland’s stand-out forwards over the past few years and his absence will be a blow to national coach Gregor Townsend as he prepares for the February 2 opener at home to Italy and the visit of Ireland a week later.

Edinburgh coach Richard Cockerill revealed after Friday night’s game at Murrayfield that 27-year-old Watson seemed to have fractured his hand, which was the one sour note from an evening when a 19-10 win guaranteed, for the first time, that both Scottish pro teams are in the quarter-finals of Europe’s elite competition.

A Scotland squad which no longer includes Watson gathered at the national team’s Oriam training base in Edinburgh yesterday and assistant coach Mike Blair confirmed that he won’t be available for some weeks.

Scotland head coach Gregor Townsend. Picture: SNS

“You can assume that,” said Blair. “Italy? No. Ireland [on 9 February]? No.

“To be honest, I don’t know because he’s seeing the specialist today. But we don’t expect him for the first couple of games. It’s suspected broken. But we don’t have the official report yet.”

Townsend has added four players to the initial pool of players he named for the upcoming Six Nations last Wednesday.

With the Glasgow Warriors trio of Sam Johnson (concussion), Jonny Gray (shoulder) and Ryan Wilson (shoulder) all receiving treatment by the Scotland medical team following knocks picked up in the weekend’s defeat to Saracens, Edinburgh flanker Luke Crosbie is joined by Glasgow back-rower Matt Smith, centre Alex Dunbar and lock/second row Rob Harley.

The 31-times capped Dunbar, who has been out with a thigh injury and was left out of Townsend’s squad last week is now restored.

The absence of Watson increases the likelihood of his former clubmate John Hardie adding to his 16 caps after last appearing for Scotland in the summer of 2017.

The New Zealand-born openside, who was released at the end of his Edinburgh contract last May following a disciplinary issue, has since resurrected his career at Blair’s own former Newcastle Falcons.

“It’s great to have John back.” said the former Scotland scrum-half and skipper. “He was back in the squad this time last year and guys love the energy he gives in defence.

“He loves flying off the line, tackling people and that brings a great energy to the squad as well.

“People enjoy his ability to play the guitar and the fact he’s always got a smile on his face as well! So he’s a good addition to the squad.”

Hamish Watson to miss Scotland’s first two Six Nations matches after breaking hand