Roberto Mancini remains safe as he accuses Manchester City players of shirking responsibility after defeat to Southampton

Southampton 3 Manchester City 1

The future of Manchester City manager Roberto Mancini will not be under consideration until the summer even if, as looks likely, the club are deposed as champions. But Khaldoon al Mubarak will need to be convinced the club have made progress in the 2012-13 campaign if he is to extend Mancini's City tenure into a fifth season.

The City chairman is extremely unlikely to feel there is any point in sacking Mancini mid-season, despite 6-4 odds on that outcome after Saturday's dismal 3-1 defeat at Southampton.

While Mancini looks increasingly likely to miss both of this season's targets – the Champions League knock-out stages and retention of the title – he will argue, as he first did last summer, that he has been damaged by poor work in the transfer window.

Mancini scrapped the pursuit of Eden Hazard when costs spiralled, but he also asked for Robin van Persie, Javi Martinez and Daniele de Rossi and ended up with none of them. He was delivered Maicon, another player he was intent on buying, but has no doubt who is to blame for failure.

"When you are a top player you should take responsibility," he said. "It's not always the fault of the manager. The players should take the responsibility, if they have big balls. If not, they can't play in a top team."

It is late to again be bemoaning the possibility that a squad assembled at such huge cost may be inadequate, but the manager's denial of blame also reflects on others, such as the former sporting director Brian Marwood.

"We did some mistakes in the summer and didn't improve our team," said Mancini, whose employers could consider moving on to a figure such as Swansea's Michael Laudrup to inculcate an entire footballing philosophy.

In replacing Nigel de Jong, Adam Johnson and Emmanuel Adebayor, more than £50m was spent on five players last summer. Of those, Javi Garcia was the only one to start on Saturday, and he looked out of position at centre-half, given the run-around by Rickie Lambert and Jay Rodriguez.

If Mancini understates his own culpability, he was right about this performance in declaring: "We can lose if the other team play better than us but not like this. I don't want to see any player like today. If they play like this, they should stay at home. Usually we play well and if we don't, we put a team on the pitch but here we didn't. That was the problem. They played better than us and deserved to win. Congratulations to [Mauricio] Pochettino and Southampton."

The tribute was well deserved. While Southampton supporters were justifiably shocked by the decision to remove Nigel Adkins three weeks ago, they were mature enough not to take it out on the new man, whose philosophy of hard work, pressing and movement was perfectly demonstrated in the goals.

It is arguable that all were due to howlers by England internationals Gareth Barry (twice) and Joe Hart, but there was tenacity and imagination too. As Steven Davis, scorer of the second by courtesy of Hart's fumble, said: "You have to force people into mistakes, it doesn't just happen. Maybe people will say City didn't play well but I think that's because we didn't let them play well and put them under pressure. We will take a lot of positives from this and hopefully kick on."

Southampton have kicked on from bottom in November to six points clear of relegation now.

"Intelligent players with a great capacity to assimilate ideas and adapt," was how Pochettino summed up his new charges. In contrast, Mancini was in no mood for compliments.