soccer:Manager Roberto Mancini played down fears of a David Silva injury after he limped out of Manchester City's win in Villarreal.

City's playmaker, a star man for them so far this season, left the field clutching his back in the second half before his side recorded a 3-0 Champions League victory.

However, Mancini said afterwards he was not concerned.

He said: "I don't think this is serious. He took a knock on his back.

"Also we play again in 60 hours against QPR. I think he can recover well."

Mancini believes Manchester City can look forward to their vital Champions League clash against Napoli with confidence after sweeping Villarreal aside.

City lifted themselves above the Italians into second place in Group A with a convincing win over injury-ravaged Villarreal at El Madrigal.

Mancini said: "I think this win is important because now we have a good chance.

"We know that everything will be in Naples.

"I think it will be an incredible atmosphere. There will be 70,000 people at the stadium.

"I think it is very difficult to play but it is important to go there with this result.

"I don't think it was easy to win here but we played very well and after the first goal it was easier. That was really important."

Yaya Toure struck twice for City either side of a Mario Balotelli penalty.

City needed to be patient as Villarreal looked to press them early on but once Toure had opened the scoring after 30 minutes, the result was rarely in doubt.

Mancini added: "Villarreal were missing four or five important players but it is always difficult to win away in the Champions League.

"We had 65% of ball possession, we scored three goals. I think this was important for our confidence.

"I think we have improved, not just in the Champions League.

"It is important for us to go in the second stage, then everything can happen with us because we are a good team. We can improve a lot in the next month."

One possible worry was the sight of the brilliant David Silva leaving the field clutching his back in the second half but but Mancini was not concerned.

He said: "I don't think this is serious. He took a knock on his back.

"Also we play again in 60 hours against QPR. I think he can recover well."

Mancini's only other moment of discomfort was when he leapt up and banged his head on the roof of the dugout. He returned after half-time holding an icepack.

He said: "I took a knock - the bench here is very dangerous!"

Mancini did not know anything about suggestions some of his players may have been a target for racist chanting.

The Italian said: "I don't know this."

Mancini was also unaware that someone may have been attempting to put Balotelli off by shining a laser pen at him as he prepared to take his penalty.