Real Madrid coach Carlo Ancelotti has confirmed that Gareth Bale will miss Wednesday's Champions League game at Liverpool and Saturday's Clasico at home to Barcelona, while suggesting Isco is most likely to come into the side in Bale's stead.

Bale, who became the world's most expensive footballer in 2013 when he signed from Tottenham for 101 million euros, had started all of Madrid's games so far this season until he missed Saturday's 5-0 win at Levante, having apparently picked up a muscle injury in his lower back while shooting at goal in training the day before.

The issue did not appear so serious at first, Ancelotti told his pre-game news conference at Anfield on Tuesday evening, but further scans confirmed the winger will be absent for what are Madrid's biggest two games of the campaign so far.

"Bale picked up an injury in training on Friday, so he is not available for tomorrow or the game on Saturday," Ancelotti said. "We will see how it goes. He travelled to [Levante] as it did not seem so serious, it seemed a strain. But when we returned he had a scan which showed [a tear]."

Ancelotti's options to replace the Wales international include defensive options Asier Illarramendi and fit-again Sami Khedira, or the more attack minded Isco and Javier "Chicharito" Hernandez. He said he was happy to have such riches at his disposal, while suggesting that Isco was the most likely to play on Wednesday.

"The squad is very good, very competitive," Ancelotti said. "We also have the possibility to put players in different positions. That will help us in big games. Without Bale on the weekend James played in his position [on the right]. Isco can help us playing on the left, he played very well on Saturday. It is a very big advantage to have a squad with quality like this one."

Also missing will be centre-back Sergio Ramos, who remains a doubt for the Clasico with a calf muscle problem. Raphael Varane and Pepe are therefore likely to play in central defence.

Sure to start is Madrid's Cristiano Ronaldo, who has 17 goals in nine games for his club so far this term, but did not get on the scoresheet during five matches at Anfield for previous club Manchester United [three wins, one draw, one defeat].

"Cristiano is in a fantastic moment, doing really well," Ancelotti said. "It is impossible to do better. He is really focused and wants to try to do the best as this moment has to continue."

Asked if Liverpool's currently out of form Mario Balotelli had the quality to become a leading player like Ronaldo or Barcelona's Lionel Messi in the future, the Italian coach was diplomatic in his assessment of his countryman.

"I know Balotelli very well, he is a forward with great quality," Ancelotti said. "[But] to compare him with Cristiano is not so easy. Balotelli has a lot of quality, he is young, he wants to play well for this team. In the past he has had problems, but when a player arrives in a new atmosphere, a new league, it is not easy to get used to the culture and the transition. So we need to have patience with him."

The former Chelsea boss said he was particularly worried about ensuring Liverpool's "transition" from defence to attack [i.e. counter-attacks] were not an issue for Madrid in Wednesday's game.