Owen Farrell will be given until an hour before today’s 4pm kick-off to prove his fitness.
The England playmaker did not train yesterday at Twickenham, as team-mates put the final touches to their Calcutta Cup preparations.
With a world-record 18th successive win on the line, the management refused to give any details of his injury, believed to be a dead leg.
Asked how disruptive Farrell’s absence had been, assistant coach Paul Gustard replied: “Not at all.
“We have until before kick-off to make a decision, which means he has at least another 24 hours of recovery