Roberto Mancini under pressure as Manchester City's senior players start to turn

Some of Roberto Mancini's most experienced players are becoming increasingly sceptical about the manager's methods, with Micah Richards' critical comments about his defensive changes reflective of a wider view within the squad that the Italian has got it wrong.

The frustrations that some players have about unnecessary changes to the defence are compounded by the fact that Mancini is testing relationships to the extreme with his repeated habit of making negative public comments about players. Joleon Lescott was the latest to be the subject of some thinly veiled sarcasm, in Mancini's Amsterdam ArenA press conference late on Wednesday. There is no sense of rebellion against the Italian, whose position remains very secure, with a lucrative new five-year deal recently signed. But with City's Abu Dhabi ownership examining why the club is struggling to reach the potentially lucrative knockout stages of the Champions League, there is a feeling among some players that he lacks the interpersonal skills to bring the best out of the lavishly assembled squad. They feel they can and should be a force in the Champions League.

As City struggle to progress on the Continental stage, reports from Spain suggest that Txiki Begiristain, the former Barcelona sporting director, may be appointed imminently to the same role at the Etihad. He would join up with the club's new chief executive Ferran Soriano, who was recruited from the Nou Camp this summer. A City spokesman firmly rejected this notion as "untrue" on Wednesday night – and it is possible the reports are a bargaining ploy, as Chelsea are also interested in recruiting the Spaniard. But sources in Spain suggest that Begiristain, out of work since leaving Barça in June 2009, will bring Joan Patsy, an ex-journalist turned sports consultant, who worked alongside Johan Cruyff at Barcelona.

The doubts about Mancini's three-man defence stem from the fact the four-man unit has been the meanest in the Premier League in the past two seasons. City, for whom Mancini appointed his compatriot Angelo Gregucci as the new defensive coach ahead of this season, have kept a clean sheet only once in all competitions during the current campaign and conceded 20 goals in 12 games.

The form of Vincent Kompany, last season's Player of the Year, has dropped sharply and Richards pointed out after the 3-1 defeat to Ajax that the side had twice conceded after going to a back three. The new defensive formation caused problems in the 2-2 draw at Anfield in August and was also rolled out when Aston Villa beat City 4-2 in the Capital One Cup.

City can ill afford the loss of a potential £18.2m Champions League revenue in prize-money alone, were they to progress to the knockout stage of the elite tournament, with TV money and commercial revenues on top of that. But even the prospect of Europa League football is looking doubtful, with City bottom of Group D, with one point. That means the club – in serious need of revenues to help them meet Uefa's Financial Fair Play regime – could be competing only to retain the domestic title and in the FA Cup, by mid-December.

A number of players have also been left feeling vulnerable about their places in the side, including Lescott, whose first Champions League start of the season ended in the calamity of Ajax's second goal. "Last season we were good, not conceding many goals. We got a lot of plaudits so it's only fair we get criticism now because we are conceding more goals. But as a team we are not overly enthusiastic about the way things are going," Lescott said. "We still believe we have the players to do well in this competition. On paper our squad looks great, but paper doesn't win games, does it?"