THE substantial bulk stands as an impressive testimony to essential truths about Celtic.

Victor Wanyama invokes the example of Borussia Dortmund as he contemplates how Celtic could win a Champions League but he is far more persuasive in what he does not say, what his performances, presence and perhaps departure testify to the reality at Celtic.

Wanyama, who won the Clydesdale Bank Premier League young player of the year award this week, spoke of how Celtic could win Europe's ultimate club tournament. "Look at a club like Dortmund," he said of the German side, who take on Bayern Munich at Wembley later this month in the final. "Dortmund have come from nowhere and they are a big club now. If we work hard and stick together we can also be like Dortmund, a top club."

Dortmund, of course, are past winners and have hardly "come from nowhere" but they offer hope to sides outside the very top echelons. However, Wanyama's ultimate German influence may not be to invoke Dortmund but to bid Auf Wiedersehen, pal to Celtic.

There are many problems in Celtic emulating Dortmund but the first and most crucial is simply money. The Bundesliga club have a turnover of £150m; this will be enhanced considerably this season. Celtic's is about a third of that and influenced by the participation in the group stages of the Champions Legaue.

Dortmund, too, will be dealing in the top end of the transfer market in the summer. They will almost certainly lose Mario Goetze and perhaps Robert Lewandowski and Ilkay Gundogan. But they will seek replacements in such as Christian Eriksen, the 21-year-old Ajax playmaker, and Kevin de Bruyne, the Chelsea attacker on loan to Werder Bremen. De Bruyne is valued at £12m-plus, as is Christian Benteke of Aston Villa, who is seen a replacement for Lewandowski. Dortmund, then, are shopping in a more rarefied market than Celtic and can thus more easily absorb the blow of losing players.

Wanyama is a prime example of what must be the Celtic model. Recruited from Germinal Beerschot for under £1m in 2011, he has grown into a midfielder who will command a fee of at least £10m, with Barclays Premier League clubs lining up to bid. His replacement will be found from within the Celtic ranks or at a fraction of the selling price.

This is the Celtic reality. Unlike Dortmund, they can not rely on harnessing outstanding domestic talent but must scout and recruit from lesser leagues to fill the gaps. They must then sell when the player commands a substantial profit.

Asked about his future, Wanyama said : "I am still a Celtic player and I am going to be here next season because I still have a contract. I do not want to talk much about this because I still have a contract. At the moment, I am Celtic player."

This protestation can hardly be classed as convincing. The Kenyan cannot be expected to say anything else but the reality of football is that he will go if the price is right. This sort of business ensures that Celtic can survive and indeed prosper at a domestic level but it impinges on future prospects in Europe.

"I think I have improved a lot," said Wanyama. This is undeniable. He has lost some of his edge over the past few games but this is understandable after a season that started in August with a Champions League qualification match against HJK Helsinki. The midfielder, though, is strong, a fine header of the ball in attacking positions, comfortable in possession and a good passer when fully focused.

But what of the progress of Celtic? "As a player I believe that we can go beyond the last 16 in the Champions League," he said. "We were close to doing that but we had little bit of a problem playing as a team in the knockout stage for the first time. We have learned from our mistakes and next time I believe we can now do better," he said.

The problem for Celtic is that the "next time" involves two qualifying rounds, a knockout round and then a group stage before the last 16 can be attained. This is an onerous task and one that may have be undertaken without such as Wanyama and top goalscorer Gary Hooper.

Wanyama is solid evidence Celtic can source good players who can be an integral part of a team that beats Barcelona and qualifies from a group ahead of Benfica, tonight's finalists in the Europa League. This was an exceptional performance and should be seen as such.

Asked if his new prominence, marked by a goal against Barcelona, surprised him, Wanyama answered: "Nothing really surprises me because I believe in working hard. If you work hard it pays. I wanted to work hard when I came here to get into the team and do well. I did that and have to keep on doing the same and see where that takes me."

It will take him away from Celtic, most probably this summer. The possibility of Celtic doing a Dortmund will be severely diminished by the loss of a player who has made his mark in Glasgow and will earn riches elsewhere.