In any conversation about the greatest Champions League manager ever, Pep Guardiola should be in it. But as the years go by and the failures mount up, the Manchester City coach is drifting further towards the margins and City's latest Champions League embarrassment, which saw them lose 3-1 to outsiders Lyon in the quarterfinal on Saturday, certainly did not bear the hallmark of genius that continues to be applied to Guardiola in the competition.

To some, such a dismissive appraisal of Guardiola's greatness will be sacrilege. After all, he's already won two Champions League titles with arguably the greatest team the competition has ever seen -- the Barcelona side of Lionel Messi, Xavi, Andres Iniesta and Carles Puyol. But since guiding Barca to Champions League glory in 2011, Guardiola has not even reached another final, despite the talent and finances at his disposal, initially with Barcelona, but then with Bayern Munich and City.

Ten years ago, Guardiola was the man tipped to break all records and become the undisputed greatest manager in European Cup/Champions League history. At 49, he still has plenty of time to do that, but as City once again crashed out of the competition without reaching the semifinals, the Guardiola story is no longer about his greatness, but his repeated failure to recapture the trophy.

When you are hot, you are hot, but Guardiola has not been hot in the Champions League for almost a decade now and maybe, just maybe, his best days in the competition are behind him.

The top managers tend to amass their European Cups in a short period of years. Zinedine Zidane won three in a row with Real Madrid from 2016-2018, Bob Paisley's three with Liverpool were achieved between 1977-81 and though 11 years separate Carlo Ancelotti's first with AC Milan (2003) and his third with Real Madrid (2014), there was only a gap of seven years between the Italian's second and third.

Guardiola's gap between wins will be 10 years if he achieves Champions League glory in 2021; only Jupp Heynckes (Real Madrid 1998 / Bayern Munich 2013) has achieved a European Cup win more than a decade after his last.

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Jose Mourinho has now gone 10 years since his second, and last, Champions League success (with Inter Milan in 2010) and the Portuguese is no longer regarded as the go-to guy for glory in the competition, so why should Guardiola be any different?

Some have attempted to defend Guardiola in the wake of the Lyon defeat by suggesting the story would have been different had Raheem Sterling not missed an open goal to make it 2-2 seconds before the French side scored a decisive third. Similarly, mistakes by goalkeeper Ederson have also been cited as errors beyond Guardiola's control. Maybe so, but elite coaches like Guardiola are paid handsomely by their clubs to minimise the mistakes and shortcomings of their players. They are hired to ensure that players deliver when the heat is on rather than wilt under the pressure.

Guardiola has achieved that in domestic competitions wherever he has been, but his selection and tactics against Lyon point towards self-doubt and fear creeping into his thinking in the Champions League following too many defeats at the sharp end of the competition.

Why else would the City manager pick a team specifically designed to nullify the seventh-best team in France? Guardiola was so fixated by the pace of Lyon on the counter-attack that he picked three centre-backs and deployed a right-back -- Joao Cancelo -- at left-back. He also played two holding midfielders -- Rodri and Ilkay Gundogan -- asked Kevin De Bruyne to operate on the left of midfiel,d and chose not to select any of his creative midfielders (David Silva, Bernardo Silva, Riyad Mahrez) in the starting line-up.

The defensive selection was due to Guardiola not trusting a two-man central pairing to cope with Lyon's front two, but having been in charge of City since 2016, he has surely had enough time to identify that problem and resolve it.

It's difficult to imagine the greatest coaches allowing such problems to persist, but Guardiola chose not to replace veteran centre-back Vincent Kompany last summer and the consequence of that was borne out against Lyon. And those strange team selections and tactical tweaks only serve to confuse players, who generally prefer consistency and simplicity.

Few teams, if any, win the Champions League by changing their shape to counter the opposition. The best just back themselves to beat whoever's in front of them, and doing it their way. That approach worked for Guardiola at Barcelona, but with Bayern and City, simplicity has too often gone out of the window and it is why he continues to wait for his third European Cup. Who knows when, or if, the next one will come along?

A new name will be added to the list of Champions League-winning coaches this season, with none of the coaches in the semifinals having won it before. Maybe this season's winner will be the next big thing, going on to push Guardiola further to the fringes unless the City manager can somehow overcome the faults that continue to hold him back in the competition.