Manchester City assistant manager Ruben Cousillas has suggested that striker Sergio Aguero could be sidelined for a period of time due to a hamstring problem.

The Argentina international was substituted at half time during last night's defeat to Barcelona, which resulted in City's stint in the Champions League coming to an end.

Aguero, who was replaced by Edin Dzeko, only recently returned to the side after missing five games with a similar problem last month.

"It is very early to say, so we cannot yet say how long he is going to be out," the Manchester Evening News quotes Cousillas as saying.

"Aguero had the injury and but for that, he would have played in the second half. Apparently it is nothing serious, he felt some kind of pain in his muscle. It is more a precaution, but we are doing some tests to assess it."

City, who recently won the Capital One Cup, only have the Premier League title to focus on as they prepare to face Hull City this weekend.