Real Madrid's preparations for the new season hit an untimely snag as marquee signing Eden Hazard was ruled out of Saturday's La Liga season opener against Celta Vigo after sustaining a muscle injury in Friday's training session.

A statement from Madrid said Hazard underwent tests after training which revealed he had injured the anterior tendon in his left thigh but did not state how long the Belgian forward would be out of action for.

Hazard, 28, joined Madrid from Chelsea in June for a joint-club record fee of 100 million euros ($110.73 million), their most profile signing in a busy close season for the 13-times European champions, who spent more than 300 million euros on new recruits.

Real are also without fellow winger Marco Asensio for the start of the new campaign due to a serious knee injury, while Dani Carvajal is suspended.