Pep Guardiola will take the blame, but his Manchester City players are the real failures

Guardiola knew his side had to attack on Wednesday night in Monaco. Going into the second leg of the last-16 tie, Monaco had won 20 of their 23 home matches this season – drawing two and losing one – while they were scoring at an average of more than three goals per game.

It would have been tactically inept of Guardiola to get his City players to defend their 5-3 lead going to the Stade Louis II, and he made clear during the build-up to the match that his side must push forward from the off.

However, somewhere between Manchester and Monaco, his players lost the memo.

"All managers make mistakes but I don't think it was down to a tactical mistake,” Guardiola added.

A dreadful first half cost City a place in the quarter-final. The attacking intent that Guardiola sought was nowhere to be seen. Instead, careless man-marking came to the fore and the visitors found themselves 2-0 down at the break, without a single shot on target to their name.

The second half was a marked improvement – but in the land famed for its casinos, fortune was not favouring City, while the house took all the spoils.

An extra City goal or the denial of Monaco’s third and we would be dissecting Guardiola’s genius – ‘How Pep’s half-time team talk salvaged City’ or something along those lines. But instead we must examine what went wrong. How did a City side so overflowing with attacking flair fail to take heed of their manager’s pre-match instructions?

"It's not about the defence,” Guardiola said. “Today was not about that. Why was the second half a problem with the defence?

"Our strikers have to be aggressive and pick the ball up, but we didn't at this crucial time. That's why we are out.”

The opening 45 minutes is one the City players will want to forget, but it’ll be a half which Guardiola replays to them time and time again. As case law goes, it will be the half that he refers to when warning his players how not to approach a match.

And in stark contrast, the second half will be the one that gives Guardiola hope and the lessons learnt from this failure could have a positive effect. Previous exits in the knockout stages to Barcelona and Real Madrid in his previous job at Bayern Munich have been understandable, but this one will hurt.

That’s not to belittle Monaco’s achievement – they are certainly capable of upsetting the favourites and lifting the trophy – but City players will wake up knowing that their second-half approach over the whole 90 minutes would have seen them in Friday’s last-eight draw, while Guardiola’s record would have remained somewhat intact.

The City players didn't ignore Pep though, they were simply daunted by the task. There’s a clear mentality issue within City and it’s one that needs addressing, and refreshing. Guardiola is used to managing teams brimming with winners, but this side is bereft of confidence, while few have sampled European success.

Guardiola must somehow exert his belief and winning mentality into the players, and while he refused to blame those misbehaving at the back, it's clear his defence really is the problem and is in desperate need of a change. It will likely get just that in the summer, with Bacary Sagna and Gael Clichy no longer the full-backs they once were - a point made even more abundant when watching the Monaco duo of Djibril Sidibe and Benjamin Mendy.

Aleksandar Kolarov at centre-back is an experiment worth dropping, while there's only so long City can wait on Vincent Kompany. If he's fit, great, but leaders must be reliable and ever-present, something no longer the case with their captain - though it's hardly breaking news either.

If fresh faces arrive in defence for City then they can be a force next season, but it's the mindset that Guardiola must somehow fix. This has already proved to be his biggest test in management, but now it’s just got tougher.