Manchester City defensive woes have deepened as manager Pep Guardiola announced that John Stones will be out for around five weeks with a muscular problem.

The England centre-back suffered the problem in training ahead of their Champions League opener against Shakhtar Donetsk on Tuesday.

"He (Stones) is out four, five or six weeks. He was injured in training this morning. It is a muscular problem," Guardiola said.

Stones' absence will add to the defensive problems for Guardiola, with French centre-back Aymeric Laporte already likely to be ruled out until the New Year.

"For me as a manager it is an incredible challenge. But I believe in something people don't know about - spirit and commitment. We will make steps forward to solve this problem," Guardiola added.