City boss Manuel Pellegrini was already toying with the idea of buying another shot-stopper in the new year, but that has been boosted with Hart’s recent run of costly errors.

And top of the wish list is Celtic ace Forster – who will be tracked by City scouts in the coming weeks as the club line up an offer for the 25-year-old.

Manchester United and Barcelona are also known to hold an interest in Forster, who has sparkled for Celtic in both the SPL and Champions League in recent months.

Celtic have already confirmed they are aware of huge interest in the player – and would not stand in his way if a top club came in for him.

It’s thought the Bhoys would want at least £10million for their star man, but City could throw players into the deal to get the transfer done.