Manchester City striker Sergio Aguero is thought to have picked up his mysterious foot injury while he was riding his son's mini-motorbike.

The Argentine has been ruled out of his side's Premier League clash at Sunderland on Saturday with the problem.

City boss Roberto Mancini had simply described the injury as "stupid" to reporters at a press conference on Friday without revealing its cause.

However, Aguero hurt his foot while he was playing with his three-year-old son on the vehicle at his Cheshire home, according to The Mirror.

The Blues can temporarily return to the top of the table with a win against the Black Cats this weekend.