Yaya Toure's agent says Pep Guardiola is overrated as a manager and worries the Spaniard would look to sell his client should he take over at Manchester City.
The Bayern Munich boss, who is favourite to take over from Manuel Pellegrini at the end of the season after revealing he wants to work in the Premier League, sold Toure when the pair were at Barcelona.
Guardiola will leave Bayern at the end of the current season, with former Real Madrid and Chelsea manager Carlo Ancelotti replacing him at the Allianz Arena.
According to Sky sources in Germany, Guardiola will undertake his first role in English football next summer by replacing current City manager Manuel Pellegrini at the Etihad Stadium.
Guardiola has confirmed he has "some offers from England" but that he has not signed an agreement at this stage.
Dimitri Seluk, Toure's agent, admits the prospect of the Spanish coach joining City concerns him and told the Sunday Mirror: "Pep is a great coach. But he has won the title at Barcelona and Bayern Munich.
"The truth is that my grandfather would win the title with Barcelona and Bayern Munich because they are big clubs with great players.
"I'd like to see Pep take a club that is eighth or ninth and make them champions."
Guardiola sold Toure to City in 2010, the Ivorian not fitting into his plans for Barcelona.
Seluk added: "I don't know what Guardiola's plans are, but - after what happened at Barcelona - of course it is a worry that when he comes Yaya will be out. I hope not and Yaya hopes not."
Toure himself has been in the news recently for criticising the decision to award the African Player of the Year title to Borussia Dortmund and Gabon striker Pierre-Emerick Aubameyang.
The midfielder, who has won the award in every year since 2011, felt he should have been the recipient this season after leading the Ivory Coast to the Africa Cup of Nations.
"I am very, very disappointed. It's sad to see Africa react like this, not giving any importance to African (competitions)," he said.