Battle lines are drawn, but will control of terrain prove critical?

"The short answer is yes," says Ian McCall, the former Rangers player and Dundee United manager, who knows something of both playing at Ibrox and preparing a side to visit the home of Rangers.

McCall, who has watched both sides closely in his role as a pundit for Radio Clyde as he seeks to get back into management, said: "Of course, Rangers winning against United and then, say Aberdeen, would be a surprise. But do not discount the Ibrox factor in the semi.

"The home ground and the support offers Rangers something that could be translated into a slight advantage. The final would then be a one-off game and much stranger things have happened."

McCall, who played for Rangers for two seasons from 1987, was blunt about the respective playing strengths of United and Rangers.

"Man for man United are the better side," he says. "But there is quality in the Rangers team. Cammy Bell, the goalkeeper, is first-rate and Lee Wallace is the best left-back in Scotland. Andrew Robertson of United is an excellent prospect but Wallace at the moment is stronger.

"Rangers also have a core of [SPFL Premiership] players. There will be those who say that they don't play like that every week but, believe me, it is difficult to raise your game when you know you are simply miles better than the opposition. Look at the second half of the Albion Rovers match. At 2-0, it became a practice match with Rangers moving the ball around at will."

There have been questions that Rangers may not be able to step up immediately to the pace of top-flight opponents and McCall concedes that can only be proven on the day.

McCoist's side has played with a lack of energy at times but McCall, who managed United from 2003-2005, said players react to the opposition and the degree of difficulty.

He points out Lee McCulloch, David Templeton, Dean Shiels, Jon Daly, Ian Black, Richard Foster, Stevie Smith, Wallace and Bell have played in the top division. "Some of them might not be there when Rangers return to the top flight but they have the experience," he says.

He adds: "The more interesting question is how the United players step up to the challenge. They have a wonderful crop of youngsters with a fast-moving and technically adept front four. But if anyone freezes on a big day, it is normally the flair players. Their game is reliant on confidence. Their game involves taking a wee chance, having an assured touch. That is a test in an intimidating atmosphere. They will not outbattle Rangers, they will have to outplay them." The importance of confidence to the United gameplan can, he says, be gauged by the blip that United endured over the festive period. "When they play well they are the best footballing team in the Premiership but when they play badly they can be accused of being the worst," he says.

The visit of United to Ibrox on April 12 offers both a challenge and the chance for redemption for a Rangers management team that has faced criticism.

"There is no doubt that Ally and his staff will be looking forward to this one," says McCall. "They are in a no-win position in League 1. When they win easily, everyone says: 'So what?' When they draw, there is an absolute outcry."

McCoist was certainly playing it canny as the build-up started immediately after his side's facile victory over Albion Rovers at New Douglas Park.

The Rangers manager has been irritated by some of the coverage of his press utterances and was offering little in the way of pre-match hoopla over a semi-final that must be considered one of the biggest matches he has encountered as a manager.

The former Rangers striker has managed in Champions League qualifiers and in Old Firm matches but he now has an opportunity to take a third-tier side to a Scottish Cup final in a season that has resonated with a damaging off-field clamour.

"It is a tough one. Everyone will have different opinions on it," said McCoist in response to questions about favouritism going into the tie. "The one thing I do firmly believe is I don't think favouritism will matter at all once the game starts.

"Different people will have different opinions. United are a very, very good side. They have got a lot of good, young talent and a bit of experience as well. I am not sure who will be favourites but I don't think Jackie or myself will be bothered who is favourite."

Rangers beat Motherwell at Ibrox in the League Cup in September 2012 but were subsequently beaten handily by Inverness Caledonian Thistle and United defeated them in the Scottish Cup at Ibrox in 2012 and last year at Tannadice.

"I hope [the gap has narrowed]," said McCoist. "We believe we are stronger than we were last year and we believe we have signed some good players. I would have to say United look stronger as well. On their day they are certainly one of the better teams in the country. There has probably been an improvement in both sides."

Jon Daly, the former United striker who is now at Ibrox, was similarly non-committal but admitted Rangers would have to play at their very best to prevail.

He played down any advantage offered by the game being at Ibrox. "It is a semi-final, it is a one-off game, it is going to be a great atmosphere and I am sure it will be a fantastic battle," he said.

But how will the war be won? And who will be the victors? Will the strength and touch of Nadir Cifti unsettle the oft-times erratic Bilel Mohsni? Can Rangers players such as Black and Shiels prove conclusively that they are not only internationalists but midfielders who can influence a game against Premiership opponents?

Will the nous and physicality of Daly prove too much for the callow John Souttar? How will the slight Ryan Gauld perform in what will initially at least be a trial of strength? Will he be negated by Wallace of Rangers and will Gary Mackay-Steven of United make a mark? Questions, questions. They will be answered conclusively in the cauldron of Ibrox.