Marco van Basten has told Sports Mole that the sheer number of current "big rich clubs" in Europe is the main reason as to why it is so difficult to retain the Champions League.

Under the competition's current guise, which has been in place since 1992, no side has been able to win the trophy back to back, while the last team to achieve the feat was Van Basten's AC Milan side, who beat Steaua Bucharest and Benfica in 1989 and 1990 respectively.

There have been many theories bandied around as to why that is the case, but Van Basten, who is Nissan's ambassador for their UEFA Champions League final activity in Berlin, believes that the fierce competition throughout Europe makes it almost impossible to replicate the success that Milan had 25 years ago.

"You need luck, but the situation has changed. Now, you can predict most of the teams that will be in the last eight of the Champions League - Barcelona, Bayern Munich, Juventus, Chelsea, Manchester United and PSG for a start," said the 50-year-old.

"These are the big clubs with the big money, but 20 years ago it wasn't like that. When we played, we had just a few good teams. In my time it was Marseille or Benfica, but not so much as now.

"There are perhaps 10 big rich clubs that are dominating European football, so they will be in the quarter-finals. If you want to make the final and win it, you have to beat many big clubs and that's not easy. You can win it once, but winning it twice is so difficult."

This year's final, which will be played on Saturday evening, sees Barcelona take on their Italian counterparts Juventus.

Marco van Basten is a Nissan ambassador for the UEFA Champions League final, where they will be harnessing fan energy to power the trophy to the Olympiastadion in Berlin on June 6. Search 'Nissan UEFA Champions League' for details.