Manchester City striker Sergio Aguero faces an anxious 48-hour wait to discover the extent of a hamstring injury he sustained in his sides victory over Stoke yesterday, the Telegraph reports.

The Argentina international scored his eighth league goal of the season, continuing to show signs that he was beginning to get back to his best following a slow start to the campaign.

Aguero will now definitely miss Manchester City's FA cup third-round tie against Watford on Saturday and is a doubt for their league clash at Arsenal a week later.

“It’s bad enough that he won’t play on Saturday,” said first team coach David Platt.

“It’s difficult to assess an injury like that for how long it’s going to be. On Saturday, he will be out. He’ll be doubtful for Arsenal. It’s a hamstring. There are different degrees of hamstring, that’s why you need the 48 hours. We’ll just have to see.”

The news will come as a huge blow for City boss Roberto Mancini who had seen his side struggling for goals recently, before hitting four past Norwich and three more yesterday against Stoke, performances in which Aguero was an integral part of alongside Edin Dzeko. City have cover in forward positions from the likes of Carlos Tevez and the unpredictable Mario Balotelli. However with key midfielder Yaya Toure set to depart for the African Cup of Nations along with his brother Kolo, Mancini won't want to lose other key players from any areas of his team.