Sergio Aguero's return to full fitness looked to have suffered a setback on Thursday when he stayed down following an Aleksandar Kolarov tackle during a Manchester City training session.

The Argentinean striker has only started 73 games in three years at City, after suffering injuries in every season he has been at the club.

He appeared to be getting back to full fitness with two goals in the first two games of this campaign, so boss Manuel Pellegrini will be hoping the knock turns out be nothing serious.

Crunch: Sergio Aguero is taken out by Aleksandar Kolarov in Manchester City's training session on Thursday

Staying down: Aguero lay on the ground following the tackle by Serbian left-back Kolarov

Concern: Kolarov and James Milner look down at their stricken team-mate after the tackle

It took the forward just 23 seconds to score against Liverpool on Monday after coming on as a substitute, in a game in which understudy Stevan Jovetic scored twice.

The form of Jovetic and Edin Dzeko would soften the blow of an injury to Aguero, but it would still be frustrating after the niggles the Argentinean has had with since joining in 2011.

Frank Lampard also took part in Thursday's training session, and he'll be hoping to feature on Saturday when the Premier League champions take on Stoke at the Etihad Stadium.

That's the way to do it: Lampard takes a shot while his new City team mates watch on in Thursday's session

A little help? Kolarov looks away before tending to Aguero, who has scored in both of City's games this season

Coming to get you: Kolarov goes charging after the ball in the incident that hurt City's star striker

Main man: Aguero came off the bench and scored within 23 seconds against Liverpool on Monday

Practice makes perfect: Aguero displayed the almost identical technique when he scored against Liverpool