Posh will travel to Reading if they overcome West Bromwich Albion in cup replay.
Should Peterborough United overcome Premier League side West Bromwich Albion in the Emirates FA Cup fourth round replay at the ABAX Stadium, they will face Championship side Reading away in the fifth round after the draw was made live on BBC 1 following Chelsea's 5-1 victory at MK Dons.
The Royals defeated League One side Walsall in their fourth round tie. The potential tie will take place over the weekend of the 19th February.