Real Madrid coach Zinedine Zidane was at a loss to explain Eden Hazard's latest injury setback that is set to rule him out of Tuesday's match against Atalanta.
The Belgian international joined Real in a €150 million ($178.83 million) deal in 2019 but his time at the Bernabeu has been blighted by injuries, making 25 La Liga appearances since signing.
Hazard returned to action as a second-half substitute in Saturday's last-gasp La Liga win over Elche after recovering from a muscle problem, playing the final 15 minutes.
Zidane said Hazard will miss Tuesday's Champions League home last-16 second leg with Atalanta and cannot put a timeframe on his return.
"He won't be fit. We'll release a statement but I can't say any more than that," Zidane told a news conference.
"They're things that I can't explain. I want to be positive and hope that it's not too much of a problem.
"Something's up, because he was never injured in his entire career [before joining Real] or there were very few injuries. It's something new. I can't really give any more of an explanation. We want to help him and hope he's back as soon as possible.
"We're going to try and figure out why it's happening [the club's injuries], but right now we can't explain it. We've spoken about things like the lack of pre-season, amount of games and the mental aspect."
Hazard, 30, joins Casemiro on the sidelines for the Atalanta game, with the Brazilian suspended after picking up a booking in the first leg, however captain Sergio Ramos is fit and likely to start.
Real won last month's first leg 1-0 in Bergamo thanks to a late Ferland Mendy strike.
