City face an anxious wait to discover the extent of an injury Sergio Aguero sustained in Argentina's 2-0 World Cup qualifier defeat against Ecuador.
The City striker's evening ended after 24 minutes when he pulled up sharply, holding his left hamstring while chasing a long ball.
He was stretchered off in tears and replaced by former Blue Carlos Tevez.
Argentina boss Gerardo Martino said later: "He had been carrying a knock with his club, during the week we took good care of him. He was moving around the pitch well, but unfortunately he felt some discomfort and we are going to lose him.
"I haven't spoken to the doctor but I can confirm the injury is not the same as the one he had been carrying with his club."
Nicolas Otamendi, who also started the game, added: "He had been having a great time and was playing well."
Pablo Zabaleta and Martin Demichelis were unused subs on a night that went from bad to worse for the Albiceleste who conceded goals in the 81st and 82nd minutes - the second scored by ex-City striker Felipe Caicedo - to get their qualifying start off to the worst possible start.
Kun, who hit the form of his life with five goals against Newcastle last weekend, is likely to have a scan in the next few days and mcfc.co.uk will bring you updates as and when they are released, though it seems safe to assume the Blues' No.10 could miss a number of key games as he recovers from his injury.