Real Madrid right-back Danilo is expected to be out of action for up to a month after being diagnosed with plantar fasciitis in his right foot.

"A tear in the plantar fascia has been diagnosed in his right foot," Real Madrid said in a statement on their website on Thursday without stating how long the player will be sidelined.

However, reports in the Spanish media suggest the Brazilian international will miss up to four weeks, ruling him out of Real's Champions League opener against Shakhtar Donetsk on Tuesday and the Madrid derby away to Atletico in La Liga on October 4.

The 24-year-old has made just two appearances for Los Blancos since joining from Porto in the close season for 31.5 million euros ($35.2 million, £22.9 million).