Real Madrid coach Zinedine Zidane has said he is at a loss to explain forward Eden Hazard's latest injury setback.
The Belgian international joined Real in a 150 million euro ($178.83 million) deal in 2019 but has been blighted by injuries, making 25 La Liga appearances since signing.
After returning from a muscle problem for the final 15 minutes in Saturday's last-gasp 2-1 win over Elche, Zidane said Hazard will miss Tuesday's Champions League home last-16 second leg with Atalanta.
"He won't be fit. They're things that I can't explain. I want to be positive and hope that it's not too much of a problem," Zidane told a news conference.
Real said in a statement that Hazard is suffering from a psoas - the primary muscle connector between the body's trunk and lower limbs - problem but gave no indication of a likely timescale of his absence.
"Something's up, because he was never injured in his entire career (before joining Real) or there were very few injuries," Zidane said.
"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.
{{/usCountry}}"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.
{{/usCountry}}"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."
The 30-year-old Hazard joins Casemiro on the sidelines for the fixture against the Italians, 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.