Roberto Mancini feeling the heat at City

The departure of Phil Batty as Manchester City's first-team doctor was not a story that hit the headlines last week. It may be a mere ripple in the tide of stories surrounding the world's richest football club but it also one that reveals tensions that exist at the club at the moment.

This is a big week for City and for Roberto Mancini. On Wednesday they face Borussia Dortmund in the Champions League. Having lost, albeit thrillingly, away to Real Madrid City will feel they must win this tie if they are to qualify from the group. The pressure is on.

As so often at Eastlands the tension involves manager Mancini, whose abrasive, single-minded style has been discussed at the highest level within the club where he remains so rated and valued.

While awarding Mancini a new five-year deal in July, ending speculation that he might leave and join Monaco, City hoped that the Italian would soften, a little, his confrontational approach and his stubborn man-management.

Maybe it is simply Mancini's exacting standards and his desire for perfection - but 14 months after Dr Batty was headhunted from Blackburn Rovers he has left by "mutual consent". City have played down the importance of his departure but Dr Batty is highly-rated within his industry.

Mancini expressed his unhappiness with City's medical department last season despite the club having the best injury record in the Premier League (last season they suffered 50 per cent fewer injuries than Manchester United).

Mancini's frustration was most evident at the treatment of Sergio Aguero, who was administered with a spray on a foot injury that left him suffering from blisters and a boil.

Although Dr Batty was not involved in the treatment Mancini is thought to have held the doctor responsible, calling it "stupid", even though the Italian helped recruit the doctor from Blackburn.

Dr Batty's departure is a surprise given that he is so highly-rated and had been at Blackburn since 1999 before being poached by City.

Changes are constant at big clubs with big ambitions such as City, who are building a fabulous infrastructure and have an admirable ethos. But City also want continuity and do not want to chop and change - not least with managers - the way that Chelsea have done in the Roman Abramovich years.

That degree of support makes the tension surrounding Mancini all the more intriguing. In recent weeks he has struck out - voicing his frustration at City's summer transfers, and in particular the failure to sign Robin van Persie, taking a verbal swipe at football administrator Brian Marwood, another at goalkeeper Joe Hart - and admitting pushing Mario Balotelli.

In midweek Mancini was at it again. He rowed with Aston Villa manager Paul Lambert during City's Capital One Cup defeat and it was, for a man who has fallen out with Arsene Wenger, David Moyes and Mark Hughes, another familiar scenario. Mancini picking a fight is nothing new and it is said that doesn't give a damn. But City do.

Mancini is aware of the stakes. Having chopped and changed his team this season and with 14 goals conceded in the opening seven matches - and no win in four - he is also acutely aware of the scrutiny. "I understand this because everyone spoke well about City for one year and now it's negative because we are used to winning every game, scoring lots of goals, not conceding many goals but this is normal.

"We are not worried about this," he said. "The [Champions League] group is very difficult. We didn't start too well because we lost against Real Madrid and for this reason it is important to play well against Dortmund."

The Real defeat hurt more because they are coached by Jose Mourinho, who replaced Mancini at Inter Milan, and who hovers in the background dropping hints of a return to England. He covets City. City's new chief executive, Ferran Soriano, once admitted, when he was at Barcelona, that Mourinho had been the front-runner to become their coach before Pep Guardiola arrived.

As well as experimenting with a 3-5-2 formation, and integrating pounds 50?million of new signings, headed by midfielder Javi Garcia, Mancini has also brought in a new defensive coach - another Italian - in his former assistant at Fiorentina, Angelo Gregucci, who does not speak English.

"It's not a problem," Mancini said. "We started two days ago to work with the defenders because with international breaks and injuries we haven't had time to work with the same players for three days in a row."

It has been a disjointed start for City with players arriving back at different times following Euro 2012 and others, such as Gareth Barry, recovering from injury. Mancini also appears to have lost some faith in Joleon Lescott, such a key defender last season, while captain Vincent Kompany has struggled for form.

Inevitably, given the vast expense at which players were recruited, it is a headstrong dressing room with characters such as David Silva, Yaya Toure and, of course, Balotelli not slow to express an opinion, while James Milner has cut a dispirited figure having fallen down the pecking order.

One boon has been the resurgence of Carlos Tevez who, after his problems last season with Mancini, now enjoys a good relationship with the manager."I was happy with the way he worked in pre-season and the way he played in the first three or four games. I'm happy and the relationship is good," he added.