They face a tough task as they must travel to Carrow Road, having frawn the original tie 1-1 at home.
But if they can pull off a shock triumph then they will travel to Stamford Bridge.
If Bristol City can overcome Premiership side Middlesbrough at the Riverside Stadium then they will host Championship outfit West Bromwich Albion.
Fifth round draw in full:
Chelsea vs Blackpool/Norwich City
Watford vs Ipswich Town
Preston NE vs Manchester City
Plymouth Argyle vs Derby County
Manchester United vs Reading
Arsenal/Bolton Wanderers vs Blackburn Rovers
Bristol City/Middlesbrough vs West Bromwich Albion
Fulham vs Tottenham Hotspur