Yaya Toure fears rivals have worked out Manchester City.
Saturday's struggle against basement boys Reading was typical of City's patchy campaign as they failed to turn their dominance into goals.
Toure, whose side travel to Sunderland today, said: "Whereas perhaps we caught a lot of teams by surprise last season, this year our opponents know how we play.
"Sometimes we have to change our system to try to break teams down. The other teams and players can analyse how we play, study our systems and styles and work out ways to stop us. Even sides who are near the bottom of the table are more than capable of making it difficult.
"A team that lost 4-0 against us last season will have learned and will change their tactics."