| Toure tested positive in a routine examination leaving City with no option but to suspend him [GALLO/GETTY]
The surprise suspension of defender Kolo Toure over a failed drugs test has dented the chances of Manchester City’s trophy chase.
Toure was suspended by the English Football Association on Thursday after testing positive for an unidentified banned substance, and faces a maximum suspension of two years.
The 29-year-old Cote d’Ivoire international was informed by the FA that he tested positive for a "specified substance'' after the English Premier League Manchester derby on February 12.
Toure was suspended "pending the outcome of the legal process,'' but has received backing from his former manager Arsene Wenger who has said Toure took a diet supplement belonging to his wife.
Coach Roberto Mancini must manage without his former captain for the immediate future at least.
While Joleon Lescott and Jerome Boateng coped well in the heart of defence in the midweek 3-0 FA Cup win over Aston Villa, they do not have the experience of Toure which could be vital in their pursuit of the FA Cup, Premier League and Europa League.
Mancini complained last week that he had "only 15 fit players" to cope with a cluttered fixture list and that his players were not "machines", suggesting tiredness would hamper the world's richest club's bid for a first trophy since 1976.
He will hope that Toure's usual central defensive partner Vincent Kompany recovers from a bruised hip in time for Saturday's home league game against Wigan Athletic to ease the impact of the Ivorian's absence even if there is no way of avoiding the inevitable media glare.
Neither City nor the FA have said which banned substance was found in Toure's sample. The World Anti-Doping Agency defines a specified substance as one that is "more susceptible to a credible, non-doping explanation.''
If Toure can prove the substance was present for reasons other than to improve performance, any ban is likely to be considerably shorter and he could even be given only a warning.
Wenger said he had spoken to the former Arsenal centre back and does not believe Toure took a performance-enhancing drug.
"He [Toure] wants to control his weight a little bit because that's where he has some problems and he took the product off his wife. That's why he was caught."
Former manager Arsene Wenger
"He wants to control his weight a little bit because that's where he has some problems and he took the product off his wife. That's why he was caught,'' Wenger said.
"He was not cautious enough.''
Wenger knows Toure well from the player's seven-year spell at Arsenal and said he doesn't "suspect him at all to have taken drugs to enhance his performances.''
"I had Kolo Toure here for years, I brought him here,'' Wenger said at a news conference in London.
"He is a boy who has a clean life, very honest living, always at home, a family man.
"I just think it is a mistake by forgetting to ask, 'Can I take that?'''
Toure has until Wednesday to decide whether he wants his backup "B'' sample tested.
Scottish player Simon Mensing, who plays for Hamilton, recently served a month long ban after testing positive for methylhexaneamine, a stimulant found in diet supplements.
The substance has been behind a spate of recent doping cases, including those of the South Africa rugby players Bjorn Basson and Chiliboy Ralepelle on the Springboks' tour of Britain in November.
Toure joined City from Arsenal for $23 million dollars in 2009 and was captain under former manager Mark Hughes before losing the armband to Carlos Tevez for this season. His brother Yaya Toure also plays for City.