Martin Johnson has warned England how desperate Scotland will be to wreck their Grand Slam dreams at Twickenham a week on Sunday.
England, on a high after Saturday's 17-9 victory over reigning champions France, are chasing their first RBS 6 Nations clean sweep since Johnson was captain in 2003.
In contrast, Scotland are in danger of picking up the wooden spoon after suffering successive defeats to France, Wales and Ireland.
The Scots have ruined England's Grand Slam ambitions before, at Murrayfield in 1990 and 2000. Now they have the chance to do it at Twickenham - and save their own season at the same time.
"They will come down and they will be desperate," Johnson said.
"They had a good autumn and beat South Africa but results haven't gone their way.
"It will be a real tough, tenacious, under-rated Scotland team that will come down and that makes them dangerous."
England number eight Nick Easter picked up the theme, adding that Scotland's form heading into the Calcutta Cup showdown will mean nothing come kick-off time.
"The Scots against the English with the history involved - the Calcutta Cup is the oldest game - they always seem to raise their game," Easter said.
"They will come at us ferociously. We're under no illusions; it's going to be a tough Test match.
"The squad are aware of it. We will try this week to get our game right tactically and then next week there'll be a little bit more emotion built into it.
"It don't think it will be that difficult to get our mindset right - we certainly won't read anything into their results.
"As I know only too well from the last three Scotland games I've played in they are always tight, physical affairs."
Andrew Sheridan has been ruled out of the remainder of the championship with a torn calf.
England expect Toby Flood to be fit for the Scotland game but they will take no risks with him in training this week.