Gareth Bale is likely to be out for a month after the Real Madrid forward sustained a calf injury in Sunday's El Clasico loss to Barcelona.
Real confirmed that Bale injured his left calf - diagnosed as a "grade two injury" - with reports suggesting the Welshman will miss around four weeks of action.
The injury means Bale is set to miss both of Real's Champions League semi-final legs against Atletico, on May 2 and 10 respectively.
Following the tests carried out on Gareth Bale by the Sanitas Medical Services, the player has been diagnosed with a grade 2 injury in his left calf. His recovery will continue to be assessed.
Wales boss Chris Coleman has told Republic of Ireland to forget about trying to goad Gareth Bale in their World Cup qualifier.
Real Madrid forward Bale returns from a two-match La Liga ban at Athletic Bilbao on Saturday after being sent off against Las Palmas.
Bale picked up the second red card of his career for shoving Las Palmas midfielder Jonathan Viera to the ground during an ill-tempered 3-3 draw.
But Coleman is confident Bale will keep his head in the white-hot atmosphere of Dublin's Aviva Stadium next week.
Anybody sensible looking at him will see he never does that. I don't even know what happened. But he is a human being and sometimes you do something and regret it.
If you look at his past, though, and he has been kicked from pillar to post, I won't be worried.
I remember when we played Scotland and some ex-Scottish player said, 'He can't play if he hasn't got any legs.'
I looked at that and thought, 'Does he really seriously think that is going to bother him?' If you look and see where he is playing, under the pressure, in the spotlight, week in, week out...
So whatever the opposition have got planned for him, he's seen it before and dealt with it before. I'm not at all worried.
Gareth Bale is set to make his first appearance since November after Zinedine Zidane announced the Wales international will be in the Real Madrid squad to face Espanyol this weekend.
Bale has been sidelined since undergoing surgery on the ankle tendon damage he suffered during a Champions League match against Sporting Lisbon almost three months ago.
Madrid coach Zidane said last week that he hoped to have Bale available again before the Champions League last-16 second leg against Napoli on March 7, but the 27-year-old forward has already returned to full training and is now set to be involved against Espanyol.
Zidane told a pre-match press conference, reported on the club's website: "He will be in the squad and the plan is for him to have some minutes. We're keen and he's keen as well.
"Bale is a very important player for us. We know the quality and speed that he has, and the damage he can cause the opposition.
"He's very happy to return to the team, to be with us, and be able to play again."
Gareth Bale has given club and country a boost by returning to training.
Bale has not played since November because of ankle surgery, but Real Madrid tweeted a photograph of the 27-year-old training at their headquarters on Sunday.
News of Bale's imminent return will please Wales boss Chris Coleman ahead of next month's vital World Cup qualifier against the Republic of Ireland in Dublin.
Real Madrid forward Gareth Bale risks missing El Clasico after suffering an ankle injury while on Champions League duty.Read the full story ›
Wales superstar Gareth Bale has signed a Real Madrid contract extension that will keep him at the Bernabeu until June 2022.
Bale joined Real from Tottenham in 2013 for a then-world record fee of £85.3million, signing a six-year contract at the Bernabeu.
He will appear in a press conference on Monday to talk about his fresh commitment to the Spanish giants.
Gareth Bale says Wales are heading into Euro 2016 with 'no fear' and hopes his experience at club level can help the team.Read the full story ›
Andy King believes Wales can defy the odds at Euro 2016 after the midfielder landed the Premier League title with 5,000-1 outsiders Leicester.
Wales are 80-1 to become European champions when making their first major tournament appearance for over half a century. And the midfielder believes the sky is the limit for the Welsh, who he feels have an edge over rivals in France thanks to having the tournament's best player in their ranks.
King has been part of one of football's greatest ever surprise story this season, and now he feels Wales can emulate Leicester's success at the Euros, with Real Madrid forward Gareth Bale leading the way after he helped his own club win the UEFA Champions League.
Gareth is probably the best player in the tournament in many people's opinion, so why can't we go there and do something? We are confident we can do that.
We've got to win six or seven games compared to 38 (with Leicester). Eighty-to-one against 5,000-1. You know which one you would rather back.
We are a talented group and I believe we have the best player in the tournament.
It's been a dream season, but ask me again in six weeks and I hope I will give you an even better answer.
Welsh forward Gareth Bale has suffered a knee injury, his club Real Madrid have announced.
Real are one point behind leaders Barcelona in the Primera Division title race and it has been reported on the Marca.com website that Bale will miss the penultimate league game of the season against Valencia on Sunday.
A statement posted on Real Madrid's official website said: "Following the tests carried out on Gareth Bale, he has been diagnosed with a joint strain in his right knee. His recovery will continue to be assessed."
Gareth Bale, the world's most expensive footballer, said he was "gutted" for his former side Spurs as he congratulated Premier League title winners Leicester on an "amazing season".