The Premiership champions will be at home in the tie following the draw early this afternoon when they were the first out of the hat.
Chelsea booked their passage after defeating Nottingham Forest 3-0 on Saturday.
The matches will be played on the weekend of February 17-18.
The draw in full is :
Chelsea v Blackpool or Norwich
Watford v Ipswich
Preston v Man City
Plymouth v Derby County
Man Utd v Reading
Arsenal or Bolton v Blackburn
Bristol City or Middlesbrough v West Bromwich Albion
Fulham v Tottenham