Cristiano Ronaldo was again unable to take part in Real Madrid training on Wednesday, raising fears that the reigning Ballon d'Or holder could miss Saturday's La Liga Clasico against Barcelona.

A club statement read: "Cristiano Ronaldo worked separately from the group, while Luca [Modric] also trained alone out on the pitch as he continues his recovery process."

Zinedine Zidane's reigning champions go into the fixture 11 points behind current La Liga leaders Barca, although with one game fewer played, making a win crucial if they are to have any realistic chance of retaining their crown.

Speaking after his match-winning performance in Saturday's FIFA Club World Cup final in Abu Dhabi, Ronaldo admitted to having felt some pain in his calf following a crunching foul by Gremio captain Geromel early in that game, but said he was sure he would recover in time for the weekend's huge clash at the Bernabeu.

"I felt an issue in my calf in the second half, but I kept playing," he said after the match. "For sure on Saturday I will be fine."

The 32-year-old did not then take part with his teammates in the team's first session of the week on Tuesday at Valdebebas, and was again absent the following morning, with Madrid not having issued any specific update on the calf problem or any other potential injury.

The club statement added that Karim Benzema had returned to group training after missing the previous day's session.

"Real Madrid were in training again as they continue to prepare for El Clasico," the statement said. "The Whites continued to fine tune details ahead of Saturday's game against Barcelona (1pm CET), where they will look to end the five-title winning year with a victory in front of their fans. Zidane called up academy players [Alvaro] Tejero, Moha and [Diego] Altube for the session. The main focus of the session was ball work at a high intensity. Benzema joined the group as they carried out different possession and pressing exercises and played several matches in small spaces."

Gareth Bale has come through his return to action at the Club World Cup with no apparent ill-effects, meaning the Wales international is available on Saturday for what could be his first start in any game since late September.