Former Barcelona striker Samuel Eto'o insists that Pep Guardiola is still the best coach in the world.
Guardiola managed 10 wins from his first 10 matches with Manchester City but has since come under scrutiny following some inconsistent results.
City went six games without a victory before impressive triumphs against West Brom and Barcelona, but a draw at home to Middlesbrough and the 3-1 loss to Chelsea at the Etihad Stadium on Saturday has seen them slip four points behind the Premier League leaders.
But Eto'o, who won the treble under Guardiola in his first season in charge at Camp Nou, says the 45-year-old's position at the top of the game should not be questioned.
"Pep has everything to be a success there [at City] and, for me, he's still the best coach in the world," the Antalyaspor striker told Telefoot. "He always wants his teams to play and he will impose this idea in England.
"His great strength is that he never changes his ideas. Technically, Pep remains the best. There's nothing else to be said."
Eto'o went on to issue a warning to another former boss, Jose Mourinho, who has endured mixed fortunes with Manchester United this season.
United have reached the semi-finals of the EFL Cup and are on the verge of securing a place in the last 32 of the Europa League, but they are 10 points off the league's top four ahead of their match away to Everton on Sunday.
Eto'o, who played for Mourinho at Inter and Chelsea, believes the Portuguese is at risk of being left behind if he does not develop his methods.
"Jose has changed a lot," he said. "I discovered someone exceptional when I came to Inter. At Chelsea, it was already a bit difficult.
"He asked for three years to relaunch Manchester United, but you have to get your team playing, you can't defend continually. Football isn't like that anymore.
"Let's be clear: I've nothing against Jose. He is able to pick someone, tell him 'you are the best' and he'll have a very good game. But football is evolving."