Christopher Nkunku: Chelsea's preparation for the new season has suffered a major setback with the news that French international striker Christopher Nkunku has had a knee operation and will be out of action for an "extended period."
Nkunku, who cost 52 million pounds (66 million US dollars) from RB Leipzig, suffered the injury playing in a pre-season friendly against Borussia Dortmund in Chicago and the club has now confirmed he will be out of action for a considerable time, reports Xinhua.
