The City striker could be out for some time.

Manchester City manager Pep Guardiola has expressed worry over the injury picked up by Sergio Aguero in Saturday's win against Chelsea. The 31-year-old Argentine striker risks being sidelined for a lengthy spell after being ejected before the day's game was concluded.

Inside the 77th minute, Aguero was pictured walking around with a discomfort in his right leg following a challenge on him by Chelsea's Reece James. He was subsequently replaced with Gabriel Jesus and immediately headed straight to the dressing room.

The striker, who has already scored 13 goals for the Premier League's defending champions, is set to undergo a scan on Sunday. However, according to his manager Pep Guardiola, the injury looks quite bad.

"Hopefully we'll know tomorrow [Sunday], but the first indication is not good. I think it's a muscular injury. [We could be without] him for some days of the toughest part of our season," Guardiola said.

"The doctor says tomorrow we are going to see but he thought it was a kick but I think he stretched a little bit." 

Having ended a two-game winless run with victory against Chelsea, Manchester City looks set to take on Shaktar Donetsk, Newcastle, Burnley and Manchester United within the next 11 days. While the extent of Aguero's injury is yet to be known, it's quite likely that he may not recover in time for the aforementioned games. 

The former Atletico Madrid forward joins the likes of Leroy Sane and Aymeric Laporte in the treatment room.