As if missing out on one Brazilian superstar were not troubling enough yesterday, Manchester City are facing a battle to retain the services of Robinho, who is attracting renewed interest from Chelsea while facing the threat of disciplinary action after walking out on the squad’s winter training camp in Tenerife.

Mark Hughes, the City manager, was disappointed to learn on Monday night that Robinho had left the training camp to fly back to Brazil to address what he called a “family matter”. Hughes and Garry Cook, the executive chairman, are eager to find out the legitimacy or otherwise of Robinho’s claim before deciding whether to fine him at least a week’s wages, which equates to £160,000, but the episode has come at the worst possible time for City, with the forward becoming unsettled by a renewal of interest from Luiz Felipe Scolari, the Chelsea manager.

City stole Robinho from under the noses of Chelsea when they paid a British-record fee of £34.2 million to sign him from Real Madrid in September, but Scolari’s interest in the player has not gone away. While Chelsea are not in a position to make a bid for him this month — with Roman Abramovich, the owner, demanding that the club move towards self-sufficiency rather than rely purely on his financial backing — Robinho has been made aware that Scolari would like to bid for him again in the summer.

Cook said yesterday that he knew nothing of Chelsea’s interest in Robinho, but he did refer to an interest expressed in certain City players by Peter Kenyon, the London club’s chief executive, during negotiations over the £12 million signing of Wayne Bridge this month. When asked about City’s reported interest in John Terry, the Chelsea captain, Cook said: “I had a meeting with Kenyon but I didn’t bring up his name. He did ask about some of our superstars, but I’m not allowed to ask about his.”

Cook confirmed that an internal investigation into Robinho’s actions on Monday was taking place amid reports that the player had flown home to celebrate his 25th birthday on Sunday with his family. “I have spoken to Mark, but only briefly,” he said. “Robinho left the training ground on Monday. Until I get all the details, I don’t know much more. I don’t know why he left the camp. I will say that the Kaká and Robinho issues are unconnected. That is an unfortunate coincidence from our standpoint.”

In a statement, Robinho tried to play down the controversy over his disappearance. “I had made Manchester City aware that I needed to return to Brazil because of a family matter,” he said. “I will return to the club and I hope to sort this out as soon as possible. I feel it is important to underline that I did not return to Brazil because of the Kaká deal. I am committed to helping Manchester City become the force that the owners assured me they will become.”