JOHN Robertson last night told his Inverness Caledonian Thistle players to step out at Tannadice with a belief they can win the Scottish Cup.

The 2015 trophy-winners head to Tayside for Sunday’s quarter-final clash with Dundee United rated as the national competition’s rank outsiders.

Most bookies have them tagged as 40-1 long shots alongside Partick Thistle, but Robertson insists he has no doubt the Highlanders can repeat the incredible feat of four years ago.

Back then, Caley Thistle were a top six Premiership side who went on to taste Europa League football the following season under John Hughes’ management.

They beat St Mirren after a replay, saw off Partick Thistle at Firhill and then narrowly scraped past Raith Rovers in the quarter-finals.

But Hughes’ men produced a fantastic performance to stun Celtic in the Hampden Park semi-final, slicing through a defence featuring future Liverpool superstar Virgil van Dijk to triumph 3-2 in extra-time through David Raven’s winner.

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Falkirk were then put to the sword in the final.

Now operating on a fraction of past finances, Robertson – a 1998 medal-winner with Hearts – reckons cash means nothing come this stage of the tournament.

The Tynecastle legend said: “It’s a Scottish Cup tie – it has great romance to it.

“It will bring memories flooding back for our fans, only four years on from the club lifting the trophy.

“And it’s a chance for these players to make another piece of history by reaching another national cup semi-final.

“When you get to this stage again, the fans start believing – and that’s important.

“They will look at this cup tie and think, if we get through, remember what happened last time we were in the last four.

“It was Celtic in the semi-finals, a victory, and then Falkirk in the final. We want them to dream. We want them to believe – and we want the players to do the same.

“I’ve said before, I don’t think these players we have here realise just how good they can be or what they are capable of.

“As players they should believe and they should want to win trophies. As manager, I want to win national trophies.

“The odds are stacked against us most of the time, but if I don’t believe we can win it, how can I expect my players to believe it? And how can I expect the fans to believe it?

“I’m sure the fans are just like me – deep down in their hearts they have expectations now.

“Maybe this could be our year again.”

The all-Championship showdown, guaranteeing second-tier involvement in the semi-finals, comes just four days after the same two teams met at Tannadice in the league.

United ran out slender 1-0 winners through Nicky Clark’s penalty but it was a match where Robertson felt the Highlanders dominated in possession and chances.

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In any case, Robertson now views the previous contest as irrelevant.

He stressed: “We played very well at Tannadice, but the only statistic that ultimately matters is that United scored one more goal than us.

“We’ve got to go down and redress that on Sunday.

“Tuesday’s game is gone now. This will be an entirely different match with a bigger turn-out from both sets of supporters.

“We’ll take three or four hundred more and United are expecting seven or eight thousand. There will be battles all over the pitch and a real edge to the game.

“We’re at the stage where we want to go and win the trophy. We’ve said all along we want to win it.

“The winners of the quarter-final will, genuinely, have an incredible belief that they can win the trophy.

“United have had a wee bit of success in it since the millennium, while we won it four years ago.

“It is fresh in the minds of both sets of supporters and I’m sure both teams are absolutely desperate to get to the semi-final.

“As a club, we have had a fantastic association with this cup throughout our 25 years in existence, with shock wins in the early years culminating in that famous 3-1 victory at Celtic Park.

“There have also been semi-finals and then the achievement of 2015 in bringing the trophy home.

“This is a chance for these players to make another little bit of history by reaching a national cup semi-final.”

Caley Thistle have lost ex-Hearts and Raith Rovers left-back Kevin McHattie for three weeks with both a knee and shoulder injury.

On-loan Tynecastle kid Anthony McDonald is struggling with a groin injury, while there is also a serious doubt over ex-Rangers winger Tom Walsh, despite his return to light training.

Ex-Celtic youth Jamie McCart should shake off a hip problem to play.