Pep Guardiola jokes "maybe Mourinho is a doctor" regarding Sterling fitness

Mourinho, speaking at a press conference on Friday, then pointedly added "we all know Sterling will play" as City face his Spurs side in the Premier League on Saturday.

City manager Guardiola has denied there was anything untoward in Sterling's withdrawal and insists medics would confirm that if necessary.

He said: "Mourinho has to speak to the doctor for the national team of England and the doctor for Manchester City. Except maybe Mourinho is a doctor, I don't know."

Guardiola, speaking at his pre-match press conference, refused to be drawn into a war of words with Mourinho.

The pair had a bitter and fierce rivalry when they respectively managed Barcelona and Real Madrid but were at least more cordial when Mourinho was in charge of City's neighbours Manchester United.

And it was clear Guardiola did not want to reignite tensions now when he was asked about recent comments from Mourinho that City players go to ground too easily.

"Listen, I'm not going to answer anything about Jose," said the Spaniard. "I said the doctor because he accused us of something we have done that is not true.

"You have to speak to the doctors about these other things, don't ask me.

"I'm almost 50. I'm old enough to understand..."

Guardiola, who has won six major trophies including two Premier League titles in four years at City, this week signed a new contract committing him to the club until 2023.

The new deal has immediately sparked speculation linking City with Lionel Messi, with whom they were heavily linked during the Argentinian's contract stand-off with Barcelona last summer.

But Guardiola, who won the Champions League twice with a Barca side containing Messi, said: "Lionel Messi is a Barcelona player. I want him to finish his career there. That is what I want. I said it a thousand times. As a Barcelona fan I want Leo to finish there."

Yet whether or not City's future includes six-times world player of the year Messi, the club believe they are a far more attractive proposition with the inspirational Guardiola in charge.

Director of football Txiki Begiristain told City's official website: "We already have an unbelievable squad. We have a lot of top players.

"But the life of the squad is always changing. There are some players asking to leave, there are other players that want to come. There are players that think they want to play more than the other ones.

"So this is the natural life of a squad. So what is very, very good for the club and for my job is having Pep.

"It's quite easy to convince the players to come because Pep makes the players better. They can see an improvement and that is obvious and that helps to sign the players for Man City."