Scans this week showed that Lampard has been playing with the injury since the club's American tour three weeks ago, sparking suggestions the England midfielder would miss the start of the season.

But Chelsea claims it is only a minor problem that should not keep him out of action.

Jose Mourinho will have to decide whether to risk Lampard in Sunday's Community Shield clash against Manchester United at Wembley, but it seems likely he will play.

Chelsea's statement said: "Contrary to speculation, Frank Lampard has only suffered a minor injury, sustained over three weeks ago whilst training in Los Angeles.

"The injury has not required any painkilling injections nor affected Frank's ability to play or to take part in any one of Chelsea's training sessions."