OF all the criticisms levelled at Ally McCoist during his turbulent reign as Rangers manager, his reluctance to gamble on youth sparked a firestorm of debate.

Never mind that Lewis Macleod broke into the Gers first team as a raw laddie of just 18 and went from strength to strength under the guidance of McCoist.

No, the fact that the likes of Kris Boyd, Jon Daly, Lee McCulloch and Kenny Miller were regular starters was proof, many fans felt, that he relied too much on older players.

But Kenny McDowall, who took over as caretaker boss after his friend resigned last month, is grateful those aforementioned thirtysomethings are in his squad just now.

For McDowall believes those senior citizens could be the key to victory in the massive League Cup semi-final encounter with Celtic at Hampden on Sunday.

Rangers have been written off by many going into the first meeting between the Glasgow rivals in three years - and are 8-1 to triumph with some bookmakers.

But the Light Blues coach knows how much experience counts in the white-hot atmosphere of the Old Firm match having been in the dugout in them on many occasions when Walter Smith and McCoist were in charge.

And he recollects how much victory meant to one of the elder statesman in his team on one of the few appearances he made at Hampden in his own playing career.

McDowall was a member of the St Mirren side that upset the odds to beat a highly-fancied Dundee United side 1-0 - courtesy of an extra-time Ian Ferguson goal - and win the Scottish Cup back in 1987.

And the former forward recalls how team-mate Frank McGarvey, a veteran of memorable league and cup triumphs with Celtic, savoured every minute of that outing.

"I think the older players in the Rangers squad will probably appreciate playing in a cup semi-final much more because of the age that they are at," he said.

"I can remember playing with Frank McGarvey in '87 when we beat Dundee United. Frank had been at Celtic and down at Liverpool and he came back to St Mirren.

"Never did he think he would ever win a cup again. I will never forget his words.

"He said to every one of us: 'Enjoy this moment because cup finals don't come every day. You think you always have a chance, but they are few and far between'.

" He is so right. So I am sure that Kenny Miller, Lee McCulloch, Jon Daly, the older guys, will appreciate where they are in their careers and that it could be their last chance to win a bit of silverware in terms of cups."

McDowall added: "It is a cup semi-final and the players will want to win the game for them. That is it in a nutshell.

"There is a cup final at stake. It is a massive game for a lot of our boys who haven't played against Celtic before.

"Even the ones who have know the importance of the game. There is a cup final at stake.

"You have got to want to get to a cup final. It is the best thing in your life in your job as a footballer, to go and try to win a cup. It is the best feeling you will ever have."

Rangers have slumped to some disappointing results in the SPFL Championship this season and now look as if they will have to rely on the end-of-season play-offs to win promotion.

The Ibrox club have drawn 1-1 with part-time minnows Alloa twice and lost to leaders Hearts and their capital rivals Hibs home and away in the 2014/15 campaign.

So it is no surprise that Celtic, who have won the Scottish title three years running, are being widely tipped to stroll to a comfortable victory in Mount Florida this weekend.

Yet McDowall, who worked as a coach at Parkhead for 10 years before moving to his current club, believes his side can rise to the occasion after watching them beat top flight opposition three times this term.

The Light Blues have knocked Inverness Caledonian Thistle and St Johnstone out of the League Cup by identical 1-0 scorelines and thrashed Kilmarnock 3-0 in the Scottish Cup.

The Rangers manager added: "Celtic are a very good side. We know to win the tie we're going to have to play well and we're going to have to carry luck. I think you need all these factors.

"It's the semi-final of a cup. It's a tough game because you are so close to getting to a big game, but you can be so far away.

"But we are under no illusions, Celtic are a good team and we will need to play well to beat them.

"But cup football is cup football. It's a one-off game and so far we have done well against the Premier League teams in the cup competitions. We're looking forward to Sunday's game."

McDowall could never in his wildest dreams have imagined that he would be in the prominent position he is at the moment at Rangers going into a cup semi-final at Hampden.

"But the 51-year-old admitted he will only really enjoy it if his charges prevail on Sunday afternoon and record what would be an unforgettable victory over their fierce rivals.

"He said: "Listen, it is massive. I have been involved in enough to know how important it is.

"To be in my position is a great honour for me. To lead Rangers into a semi-final is great. I just want the result to go my way. We will see where we go from there."