The 21-year-old signed for Spanish second division club Sporting Gijon for £3.5million in the summer after spending the previous three seasons on loan.
Gijon's sporting director Miguel Torrecilla has revealed that City inserted a buyback clause in the contract which can only be activated within the next two years.
“They have an option to take him back, but it would generate a significant profit for us," said Torrecilla. “They have two years to buy him back.
“I don't want to go into numbers, but we would be talking about one of the best deals in the history of Sporting."