Last season, Athletic Bilbao were the darlings of Europe. Between February and April, Athletic played stunning football of high tempo, high risk and high entertainment. They destroyed Manchester United over two legs in the Europa League in a manner so thrilling that even most United fans simply applauded.

It was quick, it was skillful, it was muscular; it seemed like the football of the future and the fact it was being produced by a side from outside the monied elite made it all the more special.

Athletic ran out of steam last season. A small squad and the extraordinary demands placed on his team by its coach, Marcelo Bielsa, caught up with them. They lost in the finals of both the Europa League and the Copa del Rey, while falling out of the reckoning for Champions League qualification. Still, the hope was that with two or three new signings (albeit made harder by a club policy of signing only Basques) Athletic might challenge again for honors this season.

The dream has been dispelled. Saturday's win at Granada lifted Athletic to fourteenth in the league table, but when they meet Lyon in the Europa League on Thursday, Bilbao desperately need a win to resurrect their hopes of progressing to the knockout phase. So far, three games have yielded just one point. Already, it seems, we are seeing the decline of Bielsa's Athletic.

In previous eras, we might have been able to enjoy them for another couple of years, to see their maturing, to watch the dynamic shift as bright young things became established stars. The raptors would always have arrived in the end to lure away prized assets with better contracts and the promise of greater glories to come, but there would have been a window of two or three seasons when the team was allowed to grow.

Not now. This is the crushing truth of the financial structure of the modern game. It's not just that middle-sized clubs (and Athletic, lest we forget, has such a proud history that it stands alongside Barcelona and Real Madrid as the only clubs never to have been relegated form the top flight in Spain) can't afford the very best players, or that the wages they can offer are less than those at the Champions League giants; it's that the gulf is so great that any good player having a decent season will leave, not just for the money but because the chances of winning trophies are so much greater with the elite.

The thought of staying for one more season to see if a group that has grown up together can achieve a glory indelible by its rarity simply makes no sense alongside the prospect of double or treble the salary and regular Champions League football.

It's the process that is destroying Arsenal (not that Arsenal has helped itself), that led Luka Modric to quit Tottenham (and may lead Gareth Bale to depart), and that will come to Atletico Madrid (where the talk is already of whether Radamel Falco will go and but which club he will join and whether he will leave in January or June).

True, of the seven players to leave over the summer, only Javi Martinez was one of Athletic's core. He moved to Germany when Bayern Munich matched his buy-out clause of 40million Euros ($51.1m); good money perhaps but his departure came as a devastating blow. For one thing, Martinez is an exceptional player, capable of operating as either a holding midfielder or as a ball-playing central defender. But worse than that, at 24, he was the icon of the new generation at Athletic: if he wouldn't stay, then what hope of persuading Iker Muniain, Ander Herrera, Oscar De Marcos or Markel Susaeta, all gifted, all aged between 19 and 24, to stay beyond the end of this season?

And then there was the case of Fernando Llorente. At times late season, with his blend of power and finesse, he seemed unplayable. He was a center-forward who could bully a defender, and then caress a volley into the bottom corner. Tactically he was key as well, partly in providing Athletic with a threat from corners and the free-kicks the quick feet of Muniain and Susaeta inevitably won, but also because of his seeming tirelessness in leading the pressing that is so vital to Bielsa's conception of the game.

He had also expected to leave in the summer but Athletic fought tooth and nail to hang into him. It seems to have been a Pyrrhic victory: he has refused to sign a new contract and will almost certainly leave for free at the end of the season. He has appeared distracted and has started just six games this season. That might have been written off as the continuing aftereffects of last season - he was apparently so exhausted when he joined up with the Spain squad ahead of Euro 2012 that the coach Vicente Del Bosque immediately decided he couldn't play him - had it not been for the row he had with Bielsa after the derby against Real Sociedad at the end of September that led to him being sent to train with the youth team.

Something in the camp is very, very wrong. Martinez was caught last week sneaking into Athletic's training camp at night, picking up a pair of boots and leaving a message on the tactics board for his former team-mates. It all seemed very weird: what's so special about the boots? Why the apparent need for secrecy?

And then there were the videos, secret recordings of the speech Bielsa gave to his players after the defeats in the two finals. What's odd is that there were two tapes - two people recording. But who? And why release the tapes now? Bielsa actually comes across very well, calm, forceful, disappointed, aware of his own failings but asking the players to examine their own consciences for what else they could have

given. Relations between Bielsa and his board haven't been good since the summer, when there was a public spat after the coach had criticized the building work at the training ground. Was that connected?

Perhaps there is nothing amiss. Perhaps a couple of strange events have coincided to breed yet more paranoia at a club at which doubt had already taken hold. And that is especially troublesome for Bielsa because his method, so exhausting, at times so counter-intuitive, requires players to commit to it absolutely. Thursday, against a Lyon team that has won all three group games so far, feels like the final chance. Lose this, and the beauty of last season's Athletic will be just a memory.