Real Madrid winger Gareth Bale is battling for fitness ahead of Wednesday's Champions League match at Liverpool after the club announced he is suffering from a buttock muscle injury.

The 25-year-old Wales star was an unused substitute in Saturday's Primera Division win over Levante on his return from international duty, while reports in Spain said he also sat out training on Monday.

That raised doubts over Bale's availability for the trip to Anfield, as well as this weekend's El Clasico with Barcelona, although Madrid have said for now they will keep an eye on the player.

A statement on the club's website read: "After tests carried out on Gareth Bale by the Real Madrid Sanitas medical services, he has been diagnosed with a muscular injury in the right pyramidalis muscle. His progress will be monitored."

Bale played the full 90 minutes in both of Wales' Euro 2016 qualifiers against Bosnia-Herzegovina and Cyprus.

Madrid will be defending their 100% record in Champions League Group B at Liverpool, who have won one and lost one so far.