As former Glasgow Warriors play-making partner Pete Horne prepared to take the Scotland reins from him, it emerged yesterday that Finn Russell could be out of action for the rest of the Six Nations Championship.

The Racing 92 stand off has been ruled out of Saturday’s meeting with France in his new home city of Paris because of concussion protocols suffered in Sunday’s Top 14 encounter with Toulouse, but Scotland coach Gregor Townsend revealed yesterday that there are complicating factors.

“Rightly we talk about head injuries, but this is a facial injury,” he said. “Finn got a whack on the side of his cheek and jaw and we’re obviously seeing how that settles. It was still fairly swollen yesterday and that will be something we keep monitoring as well as the return to play through the HIA (head injury assessment). As with all these injuries, you can’t predict how quickly people are going to come back, particularly when it’s head injuries. We’ve two or three players who have not played since before the November tests so you can’t give definite dates when players are going to return.”

READ MORE: Scotland make four changes for Six Nations fixture v France

Horne returns to the starting line-up among four changes which were the minimum required as a result of the injuries suffered during and since Scotland’s last championship match against Ireland.

It will now be an all-Glasgow Warriors midfield as Nick Grigg replaces clubmate Huw Jones at outside centre, while Blair Kinghorn was an automatic choice to replace Stuart Hogg at full-back.

The only change to the pack sees Edinburgh’s Magnus Bradbury come in for Glasgow’s Ryan Wilson, having demonstrated his fitness on his return to action for Edinburgh after a four month lay-off, putting in a man-of-the-match performance which clearly impressed the Scotland coaches.

“It’s a credit to Magnus and the work he has put in with the Edinburgh strength and conditioning staff,” said Townsend.“We had heard lots of positive feedback about the shape he was in and that he was looking really good in training. He was 50-50 to play against the Southern Kings recently. He went out to South Africa with them. So he has been close to match-ready for two or three weeks. To see how he transferred the work he’s been doing in the gym and the training park to his performance was excellent We were hoping Magnus would come into our squad, but the way he played, he deserves this starting place.”