Can the stale Champions League group stage be revived?

The Football Observatory at the International Centre for Sports Studies in Switzerland recently found that the group stage was the most unbalanced competition in Europe behind the top divisions of Cyprus and Austria.

"I think for...Real Madrid, Barcelona and Bayern, the Champions League starts in February," Manchester United boss Jose Mourinho has said in September.

The Champions League group stage, which reaches its conclusion this week, has once again largely served to emphasise the gulf between Europe's haves and have-nots.

As a reminder, here are just a few of the scores from the competition this season: Maribor 0 Liverpool 7; Paris Saint-Germain 7 Celtic 1; Chelsea 6 Qarabag 0; APOEL 0 Real Madrid 6.

Going into this final matchday, 11 games have been won by a margin of four goals or more. A further 15 matches have seen three-goal victories, meaning almost exactly a third of the group games to date have been decisively one-sided.

The Football Observatory at the International Centre for Sports Studies in Switzerland recently found that the group stage was the most unbalanced competition in Europe behind the top divisions of Cyprus and Austria.

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What is happening is nothing new, though, and Manchester United manager Jose Mourinho summed it up in September when he called the group stage a "warm-up".

"I think for...Real Madrid, Barcelona and Bayern, the Champions League starts in February," he said.

• Teams which have already qualified
• Group B: PSG, Bayern Munich
• Group C: Chelsea
• Group D: Barcelona
• Group F: Manchester City
• Group G: Besiktas
• Group H: Tottenham, Real Madrid

We already know that nine of the teams who will feature in the last 16 come from Europe's leading five leagues — Spain, England, Germany, Italy and France — and Mourinho's aforementioned trio will be among them.

Indeed, it may turn out that only two qualifiers come from outwith that elite, with Turkish champion Besiktas already through in Group G and only one of Basel or CSKA Moscow likely to advance in Group A.

The only outsiders to make it past the group stage last season were Portuguese giants Benfica and FC Porto.

Sharing in the prestige

Going further forward, the last time a club from outwith the 'Big Five' reached the semifinals was PSV Eindhoven in 2005. PSV won the European Cup in 1988, while Celtic lifted the trophy in 1967.

The current Celtic has not lost in 67 domestic matches, a British record, with Brendan Rodgers undefeated on home soil since becoming manager 18 months ago.

But Rodgers has also overseen the club's heaviest European defeat, 7-0 in Barcelona last season, and heaviest home loss, a 5-0 reverse to PSG that preceded the 7-1 hammering at the Parc des Princes.

"We're having to make up a huge gap in terms of quality, but we're going to try to progress each year," Rodgers said after the match in Paris. "It's always going to be a challenge for us, you cannot get away from it."

The only solution to throw the tournament open again would probably be to reintroduce a straight knockout system, with no seedings, like it was before the Champions League era began.

Real Madrid and Bayern being drawn together in a winner-takes-all tie right away would be fantastic for excitement, but there is no prospect of that happening, and it is hard to envisage a better outcome than the system currently in place.

Indeed, the changes implemented in time for next season, guaranteeing four group-stage spots for clubs from Spain, Germany, England and Italy, are really a step closer to a closed league for the elite.

Celtic's most recent financial results showed overall revenue of £90.6 million (102.5m euros, $122m), while PSG came sixth in Deloitte's 2017 Football Money League with overall revenue of 520.9 million euros.

Too strong at home but not strong enough in Europe, Celtic instead makes the most with what it can get its hands on.

"These results...reflect the paramount importance to the company of participation in the group stages of the UEFA Champions League," said a report of its annual financial results, published in September.

Just reaching the group stage -- sharing in the prestige and the revenues -- has almost become the be all and end all.

For the rest, the real thing begins when the draw for the last 16 is made next week.