Manchester City assistant manager David Platt has asked the club's supporters to keep their faith in Roberto Mancini.
The Italian's decision to replace Carlos Tevez with Sergio Aguero in the second half of their 1-1 home draw with Everton in the Premier League on Saturday was jeered by the City fans.
"I don't think it is new in football," The Sun quotes Platt as saying. "People pay their money to watch a match and everybody has opinions. Certainly there's expectancy levels now from ourselves and the supporters.
"And that is healthy because that level wouldn't be there if we didn't win trophies. It is not quite as simple as one for one [substitution] sometimes.
"When you are making subs, you've got to look at everything as a whole. Everton are an aerial threat at set-pieces so we are sat there thinking 'we want to get Sergio on but what do we do? Leave one striker on, do we take a striker off, do we play with three strikers?"
City are currently three points behind Manchester United in second place in the table.