Butland's future has been the subject of intense speculation during this month's transfer window with a host of clubs chasing his signature.
The likes of Liverpool, Everton, Newcastle and Southampton have all been credited with an interest in Butland, but Chelsea have now jumped to the front of the queue for the keeper.
Birmingham boss Lee Clark has admitted that they could be forced to sell Butland due to their ongoing financial concerns.
Despite having Petr Cech as No.1 and Belgian youngster Thibaut Courtois impressing on loan at Atletico Madrid, Chelsea see Butland as a long-term investment.
It remains to be seen if Butland would make the move to Stamford Bridge as he is thought to be keen on moving to a club where he will be playing regular first-team football.
To find out more about live football on Sky sports, Click here