Former Manchester City manager Stuart Pearce believes Pep Guardiola's lack of tactical consistency is confusing his players.
Guardiola's methods have come under scrutiny in recent weeks after a poor run of form which has seen City win just four of their past 15 games.
Last weekend's 4-2 defeat to Leicester came after a 3-1 loss to Chelsea the previous week and City have now fallen seven points behind Antonio Conte's Premier League leaders.
At the King Power Stadium, Guardiola began with a back three of Bacary Sagna, John Stones and Aleksandar Kolarov, with regular right full-back Pablo Zabaleta deployed in an unfamiliar midfield role.
The Spaniard quickly abandoned that formation when Jamie Vardy scored the first of his three goals for Leicester in the third minute and Pearce believes that sends a bad message to the players.
"I was at the Leicester game at the weekend when they got beaten and they started with three at the back and conceded a goal after two and a half minutes," Pearce told Premier League Daily on Sky Sports News HQ on Wednesday.
"They changed to four at the back after two and a half minutes of a game.
"You set your team up all week to play in a certain way and then it only takes a goal after two and a half minutes to change your whole tactical approach to the game and personnel.
"The main thing coming out of Manchester City at the moment really from I can gather through friends of mine who are associated with the club is they never know what team is going to be played or what formation is going to be played in any game or at any time during any game."
City have conceded 19 league goals in 15 games this season, eight more than Chelsea and Tottenham who have both let in only 11 so far.
Chelsea can move six points clear at the top of the table if they can claim a 10th consecutive league victory with three points at Sunderland on Wednesday night.
Conte has introduced a 3-4-3 formation in which his players are thriving and Pearce believes City would benefit from a similarly-consistent approach from Guardiola.
Pearce said: "When you look at teams in the Premier League that are not conceding goals such as Chelsea, they have got a consistent line-up and a consistent shape to their team.
"I can pick Chelsea's team. I know it already - we all do - and you know the formation.
"Manchester City, I don't think actually at this moment, from the manager to the team, believe in what they are trying to achieve to get a result."