Sporting coach Ricardo Sa Pinto and goalkeeper Rui Patricio yesterday told City to under-estimate the Portuguese club at their peril.

City tackle the side currently fourth in Portugal in the last 16 of the Europa League having thrashed the country's champions 6-1 on aggregate in the previous round.

Mancini says that result has not led to any complacency ahead of the first leg of their tie with Sporting at the Estadio Jose Alvalade tonight.

The Italian said: "I played here five years ago with Inter (Milan) in the Champions League and we lost. We had the same situation the day before.

"I don't think an easy game exists in football, in the Europa League. Every game is very difficult.

"If we want to win we should play very well and have good concentration for this game.

"Sporting Lisbon are a good team and play very good football."

City's priority is thought to be the Barclays Premier League title race, which they lead by two points with 11 games remaining.

Sa Pinto and Patricio have both warned that City will pay the price if they are not focused tonight or have not done any homework on the opposition.

"My stance on football is always to be very well informed about my opponent," Sa Pinto said.

"Maybe not everyone does that and that is up to them, but after tomorrow they maybe won't forget about some of the Sporting players' names."

Patricio said: "I don't care whether they know Sporting's players or not - they will get to know them tomorrow."

Mancini brushed off those remarks, claiming he very much has his sights set on double glory.

He said: "We want to improve every year. We started last year with the FA Cup and now we have a chance in the Europa League and the Premier League.

"This is our target and we want to do this if possible."

Midfielder Gareth Barry is also wary of the threat Sporting could pose.

The 31-year-old said: "We have worked a lot on it and we know we are going to have to play a very good game to keep out the attacking players they have."

Meanwhile, Mancini last night confirmed striker Mario Balotelli had been fined one week's wages - thought to be around £120,000 - for breaking a club curfew less than 48 hours before Saturday's game against Bolton.

Mancini said: "This is normal because every player should have good behaviour before the game."