The Argentinean limped off at half time during City’s defeat to Barcelona in midweek, in what was just his third appearance since another hamstring problem that kept him out for a week.
Ruled out of today’s clash with Hull, Aguero is facing a real battle to be fit for the Manchester derby against United on the 25th March.
The derby is one of three games that City have in hand over leaders Chelsea, with Jose Mourinho’s side nine points clear going into this weekend’s games.
City’s form dipped when Aguero was last injured and Manuel Pellegrini will now rely on the likes of Alvaro Negredo, Edin Dzeko and Stevan Jovetic to fire his team back to the top of the table.
Aguero has 26 goals this season and will have a scan today to confirm the length of his absence with City set to do all they can to get him fit for the derby.