Gareth Bale injury concerns Rafa Benitez in Real Madrid's UCL win

Real Madrid coach Rafael Benitez, while happy with his team's attacking strength, is concerned about an injury to Gareth Bale after Tuesday night's 4-0 Champions League Group A win against Shakhtar Donetsk.

Centre-forward Karim Benzema put home side ahead after a mistake by Shakhtar goalkeeper Andriy Pyatov midway through the first half, and the Ukrainian side were in real trouble after midfielder Taras Stepanenko was sent off early in the second period.

Cristiano Ronaldo then stepped up to score his latest hat trick by converting two penalties awarded for handballs (one dubiously) and a close-range header after Pyatov had parried Marcelo's volley.

Less happily for Madrid were injuries which forced off Bale, Raphael Varane and Sergio Ramos, with the Welshman appearing to suffer a calf injury which makes him a doubt for Madrid's looming La Liga games at Athletic Bilbao and Atletico Madrid, as well as his country's upcoming Euro 2016 qualifiers.

The Spanish coach told his postmatch news conference that Bale had picked up a calf muscle problem, but it was too early yet to know how long the €100-million man would be out.

"Bale had a spasm in his calf muscle," Benitez said. "We must wait a day or two to see how serious it is. Gareth had a similar issue last year, so [we] must wait a while."

Benitez said the issues which had forced centre-backs Ramos [shoulder] and Varane [leg] out of the action were more minor.

"Sergio and Varane both got bangs," he said. "We will have to wait a few days, but I am more optimistic about them."

Madrid also currently have James Rodriguez and Danilo on the injury list with muscle problems, but Rafa said he was not concerned about any issue with his team's physical preparation.

"I am not worried, as I have not really had many [muscle injuries] over this time," he said. "Two today are just bangs, so the team are pretty good physically. We are pretty healthy in general."

Benitez admitted that the game had not been as comfortable for Madrid as the final 4-0 scoreline suggested.

"It was a difficult game, [Shakhtar] moved the ball well, had possession, which made it difficult for us to control the game," he said. "They had pace and were dangerous on the counter. But even not playing a brilliant game we made many chances. We have such strength in attack, so I am happy to have made many chances, while not conceding a goal."