Sporting coach Ricardo Sa Pinto 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 on Thursday night. 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."
He added: "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 has warned that City will pay the price if they are not focused 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 [the match] they maybe won't forget about some of the Sporting players' names."
Source: PA
Source: PA