David Beckham faces up to four weeks on the sidelines after breaking two ribs during England's 2-0 victory over Wales in Saturday's World Cup qualifier. Real Madrid's doctor Juan Carlos Hernandez told the club's website the injury was worse than first thought.
"Beckham has two hairline fractures, which make it difficult for him to walk and even lie down," said Hernandez.
Beckham will miss four games in La Liga but will be back for England's friendly with Spain on 17 November.
The injury also rules the 29-year-old out of England's World Cup qualifier against Azerbaijan on Wednesday.
And Beckham controversially admitted he deliberately fouled Welsh defender Ben Thatcher to pick up a yellow card to ensure the resulting one-match ban coincided with the injury.
Real sporting director Emilio Butragueno had told BBC Sport he hoped the 29-year-old would be fit in time for Tuesday's Champions League tie against Dynamo Kiev. "If anyone can return quickly from injury, it's him," Butragueno said.
But now Beckham will miss both matches with Kiev as well as league games against Real Betis, Valencia, Getafe and Malaga.
Real have had a dire start to the season. They are currently 10th in La Liga, having lost three out of their first six games.
And Butragueno believes Beckham is crucial to turning around that slump in form. "We didn't expect these results," said the former Spanish international striker.
"And we hope to change that with David Beckham in our side.
"In my mind we have the world's greatest squad and my forecast is that the team will bounce back.
"There's still a long way to go in the season - we have enough time to catch up and win the league."