The England international is under yet more scrutiny after a mix-up between himself and defender Matija Nastasic led to Chelsea's late winner in Sunday's Barclays Premier League clash at Stamford Bridge.
It was the latest of a series of errors to have blighted the 26-year-old's performances for club and country over the past year.
It would not be unusual in itself if Hart were to be replaced by Costel Pantilimon for the fourth-round tie at St James' Park, as the Romanian has often been preferred for cup fixtures in the past two seasons.
But given the increased speculation over Hart's position - after previous mistakes against Scotland, Cardiff, Aston Villa and Bayern Munich this season - the match could give him the opportunity to stake a claim for a regular place.
Pantilimon, also 26, has not played in the Premier League since joining City from Timisoara in the summer of 2011 as replacement for Shay Given.
Source: Manchester City MAD