Manager Pep Guardiola says Yaya Toure will only play for Manchester City again if he receives an apology for comments made by the player's agent.

However, it is not clear whether the City boss wants the apology from the midfielder or his representative.

Dimitri Seluk claimed Toure, 33, had been "humiliated" by being left out of the club's Champions League squad.

Seluk also said Guardiola should apologize to the midfielder if City did not win the competition without Toure.

Speaking on Tuesday, Guardiola said: "He must apologise to his team-mates. He must apologise to the club. If he doesn't, he won't play."

The Spaniard said it had been a difficult decision to leave Toure out of his European squad.

Guardiola could not include more than 17 overseas players in his squad, but had 18 to chose from.

"If he has a problem, he should speak to people at the club," said Guardiola, who was Barcelona boss when Toure was sold to City in 2010.

He added Toure, who returned to training on Monday after a migraine, had not had the "courage" to call him.

Guardiola was speaking soon after Toure announced his international retirement.

Having made his debut for the Ivory Coast in 2004, Toure won 113 international caps, winning the Africa Cup of Nations in 2015.

"Writing this note was probably 'the most difficult match of my life'," he said in a statement.

"After 14 years at the highest level, I'm sure this is the right time for me."

Meanwhile, City captain Vincent Kompany could make his first appearance of the season in Wednesday's League Cup third-round tie at Swansea.