ROBERTO MANCINI fears title-winning hero Sergio Aguero could face a long spell on the sidelines.

It’s Ag-ony! Mancini sweats over Aguero injury blow

The Argentine striker, who was taken to hospital, will need a scan on a knee injury after he was carried off after just 13 minutes.

And his Manchester City boss Mancini said: “We don’t know at the moment, we need to wait maybe two days for scans.

“We hope it is not serious but at this stage I don’t know.

“It’s his knee. I am worried, yes, but we don’t know yet. This can happen in every game.

“It is clear that it is important that you are also lucky through the year but today it’s a problem. Usually the knee is always dangerous.

“I’m worried but at the moment, we can say nothing. A good thing was he wanted to try . If it is a serious injury, we will probably change our plans.

“Maybe he is out for a week, or three or four weeks, or until after the international break.”

But last night Aguero, 24, insisted the injury was not serious.

He tweeted: “The studies I had done revealed there’s no significant injury but it was a very tough hit to my knee.

“Tomorrow, the physicians will evaluate the time it will take for me to recover. And I want to congratulate my team-mates for their effort in turning this game around.”

After Aguero went off, City were in danger of suffering a shock defeat by Premier League new-boys Saints.

Having lead through Carlos Tevez, they fell behind to goals from Rickie Lambert and Steven Davis before Aguero’s replacement Edin Dzeko and Samir Nasri saved the day for the champions.

Mancini is now likely to turn up the heat on football administrator Brian Marwood to get the City chequebook out.

He joked: “I’ve been saying that because I know we have an injury.”