Ten reasons why Man City are out of the Champions League:
1. The summer transfer window
He ended up with Maicon, who used to be one, the promising Matija Nastasic and Javi Garcia, a useful squad member, plus Scott Sinclair, Jack Rodwell and third-choice goalkeeper Richard Wright, who have made one Champions League appearance between them this season. None of the City signings have been the automatic choice Mancini envisaged. Each, in his own way, could be deemed a weak link at times.
2. The draw
To end up in one Group of Death is unfortunate. To be in two is truly damaging. City's task was difficult from the moment they were pitted with Ajax, Borussia Dortmund and Real Madrid, just as Bayern Munich, Napoli and Villarreal were daunting opponents last season.
While a second successive failure means City's UEFA co-efficient will remain low - and, assuming they qualify, puts them in danger of ending up in a third tough group next season, the reality is that it is not just the continental giants of Bayern and Real who have eliminated City: Napoli and Dortmund, two teams equally untried at this level, have acclimatised quicker and better.
3. The final four minutes in Madrid
The question 'what if?' can be posed after every failed campaign. City can ponder an alternative series of events when Aleksandar Kolarov's free kick in the Bernabeu, which put them 2-1 up, was the winning goal. Had every other result remained the same, they would be ahead of Real Madrid with a game to go.
But, as they know, Real rallied, the winning habits of Jose Mourinho and Cristiano Ronaldo apparent in their comeback. Victory would have had a psychological significance for a City side in need of a breakthrough result in Europe.
4. Double Dutch
It was branded the group of champions and Ajax have four European Cups in their sizeable trophy cabinet, but the Eredivisie winners were much the pool's underdogs. Indeed, they are yet to take a point from either Madrid or Dortmund. But, after a 3-1 win and a 2-2 draw, they have four from City and much as Mancini regrets the late loss to Real, he should be most critical of his team for their failings in the double header against Frank de Boer's side. The second half in Amsterdam and the first in Manchester were especially costly.
5. Tactical tinkering
Mancini's controversial fondness for a back three is not the unmitigated disaster some believe; it worked in the Premier League game against Tottenham and was a qualified success in Madrid. But a mid-match switch in Amsterdam backfired when, with their defence looking confused, City promptly conceded.
And starting off with a 3-5-2 formation against Real was a mistake Mancini had to remedy inside half an hour; they were exposed on the flanks and unable to cope with the Spanish champions in the centre of the park. While, as Mancini insists, top footballers should be able to adapt to any formation, City's players often seem happier playing their variant of 4-4-2.
6. Diabolical defending
Ajax scored three from corners alone and, while Mancini has been criticised for preferring zonal marking, the Italian had a point when he sarcastically said he forgot to tell Joleon Lescott to jump when Niklas Moisander headed the Dutch champions' second goal in Amsterdam. Dortmund's strike in Manchester, meanwhile, was the product of an awful pass from Rodwell, straight to scorer Marco Reus.
7. The lack of a defensive midfielder
Nigel de Jong's reputation has rarely been higher at City. Since the Dutchman joined AC Milan in August, City have used four different defensive midfielders alongside Yaya Toure with none really convincing Mancini, to the extent that he disposed of them all when selecting his side against Real on Wednesday.
Rodwell was particularly awful against Dortmund but Garcia was hauled off at half-time when Ajax visited Manchester. Only Partizan Belgrade have had as many efforts on their goal as City in the Champions League and the lack of protection afforded to their defence is a major reason.
8. Getting the balance right
When City are at their best in the Premier League, it is often with two strikers plus David Silva, Samir Nasri and Yaya Toure. That may be too attacking a formula for the more tactical Champions League, however. City are too open too often. They concede goals and are left to chase games. Late onslaughts have produced a point in each of their home matches, but stirring comebacks have not been sufficient. There was a time when Mancini was criticised for being too defensive. Now, perhaps, he is not defensive enough.
9. Strange selectionsIt was only a footnote when James Milner replaced Sergio Aguero in the dying minutes against Real but it seemed odd to take off the scorer. It was perplexing, too, that Gareth Barry was not on the bench against Dortmund, meaning that, when Garcia was injured, Rodwell came on. Edin Dzeko, the Premier League super-sub, has been granted more starts in Europe when, despite the Bosnian's return in front of goal, Carlos Tevez might have been a better choice.
10. InjuriesApart from losing both first-choice centre-backs in January, City's players stayed fairly fit as they won the Premier League. They have had less luck this season: Aguero sat out the start of their Champions League campaign, Silva missed both meetings with Ajax and Pablo Zabaleta one. Nasri was hurt in Madrid and Garcia against Dortmund while Mario Balotelli was unavailable for both meetings with Madrid and Gael Clichy missed in the second one. If every losing team blames injuries, they have nevertheless played a part in City's problems.