Is David Pizarro last piece in the Manchester City jigsaw?

Loan star can make a big impact in run-in

Pizarro on Roma’s 2008 Champions League last-eight loss to the eventual winners: “United were so strong against us that night. It was a massacre” (PA)

Massacro! David Pizarro said yesterday, recalling the humbling he experienced when he last went toe to toe with Manchester United, as he will for the next four months with Roberto Mancini at Manchester City. The occasion was the 2008 Champions League quarter-final, when Pizarro's Roma were a temporary impediment to what would be United's triumphant campaign and though Pizarro left Stadio Olimpico that night with some fairly trenchant views about Cristiano Ronaldo's showboating – "there is no doubt that he has quality but it is also true that he has a big head" – time has left him to conclude that there was simply a difference in class. "Molto bene Ronaldo," he remembered. "I could only see the back of his shirt. United went over the top that night. It was a massacre."

This time Pizarro is with the club who are ahead of United, though only on goal difference, and for those who wonder why Mancini has added another diminutive midfielder – to go with "El Kun" Aguero, City now possess the player known universally as "El Peq" because he is precisely as "pequeno" as David Silva – the answer lies in the experience which he and his new manager once shared of an almost unique type of pressure.

It was the 2005/06 season and Internazionale's wait for a Serie A title had stretched to 16 years when Mancini bought Pizarro from Udinese. Mancini's vivid recollection yesterday of the intense scrutiny that season brought – "every game is scrutinised in detail and all the journalists, all the newspapers, say the manager made this mistake, and that mistake, every game, every game ... so different from here" – led the Italian to suggest that City is a cinch, by comparison. Pizarro recalled Mancini's grace under pressure – the quality he seemed most emphatic about was "the ability to lead a group with a lot of personality". The 32-year-old described the Italian's balancing act of stabilising a club whose squad is in flux, in a way which reminded you how similar Mancini's previous and present jobs really are.

That single season at San Siro was not without its challenges for the Chilean, who spent a fair bit of it on the bench because Juan Sebastian Veron was competing for the same role, and regular football is not a guarantee at the Etihad, either. Though Pizarro in his pomp at Roma was a quick, deeply talented instigator of play, there is a feeling in Italy that he has lost some of his composure and strength over the past two years. He had become something of a forgotten man in Rome; a mere mortal in the Eternal City. That has made for some stormy relations between him and Roma's manager Claudio Ranieri – "oof!" one Italian observer said as he made this observation yesterday – and Pizarro was destined for Juventus before Mancini made a move which the midfielder clearly wasn't expecting. "It was a surprise for me as well because it was done pretty quickly and I had different ideas about changing countries," he said. "I had already quite advance agreement with Juventus but when they told me about Manchester's City's concrete interest I liked this more."

Mancini has a track record of causing frustration to veteran signings. Patrick Vieira felt he was fit enough to have played far more than he ever did, after making his own move from Internazionale, aged 33. But there won't be fireworks here. Pizarro's relationship with Mancini prevents it, as much as the player's retiring personality. Pizarro has maintained so studiously low a profile in Italy that his campaigning work to recognise the courage of the 33 miners trapped in Chile's San Jose mine in 2010 took everyone by surprise.

He has something to prove though and when he gets his chance he will be expected to dictate play, from deep, in the same way that Andrea Pirlo, now at Juventus, always has, despite often being the deepest midfielder in the side he has played for. The concept of the playmaker operating behind a more industrious and obviously defensive midfielder is more common to Italy audiences than English. "[Pizarro] can play in Yaya [Touré]'s position or Gareth [Barry]'s position," said Mancini, whose lack of creativity from deep harmed City in their Champions League campaign. A new Nigel de Jong this player is obviously not. "The referees tend to see the game differently [here]. They don't whistle a lot so I know it will be 90 minutes full on," he said.

The man for whom Pizarro's arrival seems the most gloomy portent is Owen Hargreaves, who had been expected to feature for City by now. Instead, Mancini's reflections yesterday offered fresh doubt as to whether he will ever make it back into the game after effectively two years out. "When we took Owen on it was a gamble because he had not played for two years," Mancini said. "We thought if he would be fit in two or three months, we could have an experienced player. But I can understand that for a player who does not play for two years, when you start to train every day, sometimes you can have a problem in your knee and your hamstring. Owen has these problems at this moment. I hope he can come back to play. I don't know this because I'm not in his mind but I hope for him."

Pizarro is ready to seize the advantage, hinting that the six-month free loan is one he would be happy to see made permanent. "I have already been in this situation before. When I went on loan from Inter to Roma, I stayed in Rome for six years afterwards so..." And he clearly fancies a form of vengeance for that 2-0 defeat in Rome three years ago. "Manchester United are a very strong team and we will try to win the league against them even though they seem to be more used to doing that than Manchester City," he said.