Gareth Bale is facing a race against time to be fit for Wales's crucial World Cup qualifying double-header after being ruled out of Real Madrid's La Liga clash with Espanyol.

The 28-year-old has been left out of Los Blancos' 18-man squad for Sunday evening's match at the Bernabeu, where the defending champions are looking for their first home win of the season.

Madrid boss Zinedine Zidane revealed earlier this week that Bale, who has shown signs of his best form over the past month, is currently struggling with a calf muscle strain picked up in the win over Borussia Dortmund in midweek.

Asked if Bale will still link up with his national side on Monday, Zidane told reporters: "There's no issue between Madrid and the Welsh national team. His state of fitness will determine whether he joins up with the national squad or not."

Wales will likely require two wins from two if they are to seal a World Cup qualification playoff spot, with a trip to Georgia and a home match against Republic of Ireland left to come.