SCOTLAND head coach Vern Cotter believes the shock of losing centre Alex Dunbar for up to nine months will only bring his squad closer together.

The Glasgow Warriors back was due to start for the Dark Blues when they take on England at Twickenham on Saturday - but now faces the real possibility that he could miss this year's World Cup after rupturing knee ligaments.

The SRU has announced the 24-year-old will definitely sit out the rest of the RBS 6 Nations after tearing his anterior cruciate ligament following a cruel training-ground slip.

It is the latest blow to hit a Scots squad short on luck.

They have lost all three championship clashes so far and have already seen the involvement of giant lock Richie Gray and veteran wing Sean Lamont cut short by injuries.

Stand-off Finn Russell was also forced to miss last month's last-gasp 22-19 defeat to Italy after he was handed a retrospective ban for tipping over Wales' Dan Biggar.

But Cotter hopes Dunbar's setback will unite his men ahead of their clash with the Auld Enemy. He said: "I think we can improve. We lost a bit of momentum after the Wales game with Finn being suspended and Richie getting injured.

"We've got other injuries as well. Sean is down, too, but the guys are adapting. There is a lot of character in the team.

"There is a real desire to do well and we've got this Calcutta Cup game to look forward to.

"We've lost Alex Dunbar just before we got on the plane, but I think it has tightened the team up and that's important for the Clan-ish nature of this game and this group of individuals."

Matt Scott has now taken Dunbar's slot for this weekend's battle, while Dunbar faces up to the reality it will be six to nine months before he can think about adding to his 14 caps.

He was taking part in the final training session at Murrayfield before the team jetted south when he fell to the turf clutching his knee.

Dunbar was rushed to the nearby Spire Murrayfield Hospital for a scan, but the results only confirmed Cotter's worst fears.

Dunbar's withdrawal is one of five changes Cotter has made to his starting XV.

Along with Scott, David Denton, Jim Hamilton, and Dougie Fife all come in for their first starts of the Championship, while Russell returns for the penultimate clash after serving his ban.

Edinburgh No.8 Denton replaces Johnnie Beattie after shaking off the calf strain which has kept him out of action so far.

Denton's Gunners team-mate Fife - a try-scorer against France - replaces injured wing Lamont.

Glasgow's Russell, meanwhile, starts in place of club-mate Peter Horne, while Saracens lock Hamilton takes the place of benched forward Tim Swinson.

The annual head-to-head with their southern neighbours has not been kind to the Scots recently.

They were thumped 20-0 at home last year by the English and you have to go back to 1983 to find the last mention of a Scottish win at Twickenham.

Former England prop Graham Rowntree claimed this week the Scots should expect another painful lesson - leaving Cotter to admit that was a real possibility.

"He's probably right," said the head coach. "They put 47 points on Italy, but we would like to think that won't be the case. We will be trying our best to stick with them as long as possible.

"I've got a good group of boys and we've got something in mind which we will try to execute."