CELTIC will, despite the best efforts of the coaches at Lennoxtown, probably never produce another batch of youngsters as prodigiously talented as the Quality Street Gang.

Few clubs in the world have been able to bring such an exceptional group through their youth ranks at the same time since George Connelly, Kenny Dalglish, Davie Hay, Lou Macari, Danny McGrain, Paul Wilson and others emerged at Parkhead in the late 1960s and early 1970s.

The Glasgow club continued to dominate domestically and enjoy noteworthy results in Europe around that time thanks in no small part to the contribution of outstanding Scottish players whose skills they had developed themselves. It is highly unlikely that will ever be repeated.

Nevertheless, the kids who have been handed an opportunity in the Celtic first team since Ronny Deila arrived in this country two years ago have made a definite difference to their play. They have been tipped to be integral to their future success by one of their predecessors.

Hay attends the majority of his former club’s home matches as a supporter these days and believes Deila’s willingness to give youngsters a chance has created a healthy competition for places in every position.

As they prepare to enter a crucial run of three games against Ross County, Aberdeen and East Kilbride in the space of eight days in the League Cup, Premiership and Scottish Cup respectively, he has predicted that can drive them to only the fourth treble in their history.

“I thought Celtic played exceptionally well at the weekend,” he said. “After the Motherwell defeat and the game against Partick Thistle there was criticism of the team in general and Ronny in particular.

"In the wins over Stranraer, Dundee United and Hamilton the quality of the opposition was in question. But I thought St. Johnstone gave them a far stiffer test on Saturday.

“The words I would use to describe the Celtic performance are pace and purpose. I thought it was an entertaining game and a deserved victory. You could pick fault with the odd defensive lapse, but generally speaking, I thought that, individually and collectively, they played as well as I have seen them play this season.

“Ross County will give them a good game on Sunday. They are a good team and will be up for it. In a one off cup game anything can happen. But I would say Celtic are capable of the treble on the evidence of Saturday. It isn’t impossible.”

Hay continued: “A big factor in the form they are displaying is that there is now serious competition for places. Scott Brown and Charlie Mulgrew have been big players for Celtic and will be again when they recover from their injuries. But on Saturday they weren’t missed.

“One of Celtic’s failings in the past has been that when they have been playing well they haven’t been able to maintain that level of performance. But the strength of the squad means they now can. The kids coming through have been important in creating that.

“Up front, Celtic don’t really have somebody who can come in and perform like Leigh Griffiths did. But it is different in all other areas. They have just signed this Danish defender, Erik Sviatchenko. That is more competition for places at the back. If they can play with the same pace and purpose they can win the treble.”

Scott Allan, Stuart Armstrong, Ryan Christie, James Forrest, Leigh Griffiths, Gary Mackay-Steven and Callum McGregor all featured in the 3-1 win over St. Johnstone on Saturday which sent Celtic six points clear of Aberdeen at the top of the Premiership table once again.

But the young Scot who has caught the attention of Hay, as well as many supporters, the most tin the 2015/16 campaign is teenage left back Kieran Tierney.

“He has been a revelation,” he said. “Kieran has been used sensibly by his manager and is not being played in every match. But if you picked Celtic’s best team just now he would definitely be in it. He is probably putting an edge onto Emilio Izaguirre’s game as well.

“It is not just about giving the young lads a chance in the first team. It is down to them to take it as well. Kieran is an example of someone who has done that.”

Hay, who managed as well as played for Celtic, believes the breakthrough which the likes of McGregor and Tierney have made under Deila will encourage their contemporaries just like it did back in his day.

“We had exceptional young players at Celtic when I first went there, The Quality Street Gang,” he said. “When one of us went through and started playing in the first team it was almost a challenge to the others to follow him.

“George broke through first and played in the 4-0 win over Celtic in the Scottish Cup final in 1969. The next season I broke through and became a regular. Then Lou and Kenny and Danny followed me.

"The fact that Tierney has got his chance and has taken it will give hope to the other boys in the Celtic Academy

“So will mixing with the senior players. We trained every day with the Lisbon Lions. We were on the same pitch as them most days. That helped our progression massively. When we finally got brought into the team on a Saturday the first team guys knew us and we knew them. They were instrumental in our development – and we ended up replacing them.

“The club will just get better if more youngsters come through. Financial constraints are one of the reasons they are getting a chance. But the manager has to be applauded for playing them.”