London - Louis van Gaal has been handed another potentially embarrassing FA Cup test after Manchester United were drawn against Derby in the fourth round.
Van Gaal came under fire from United fans after his spluttering side laboured to a 1-0 victory over third tier Sheffield United in the third round at Old Trafford on Saturday.
It took a stoppage-time penalty from Wayne Rooney to spare United from a replay against the Blades.
But Championship promotion chasers Derby are likely to provide another tricky tie for Van Gaal's side.
Derby, managed by former Chelsea and Real Madrid assistant Paul Clement, are second in the Championship as they chase promotion to the top-flight.
Holders Arsenal, 3-1 winners over Sunderland in the third round and bidding to lift the trophy for the third year in succession, have been handed a home tie against Burnley.
Manchester City will travel to either League Two club Wycombe or Aston Villa, who drew 1-1 on Saturday.
Liverpool were held to a 2-2 draw by fourth tier Exeter and the winner of that replay will entertain West Ham.
National League outfit Eastleigh, the lowest ranked team left in the competition, will host Championship side Leeds if they can see off Bolton in a replay.
Harry Kane's late penalty kept Tottenham in the competition and if Spurs win their replay against Leicester, a trip to third tier Colchester awaits.
Crystal Palace tackle Stoke in an all-Premier League tie while fourth tier Oxford, who stunned Premier League strugglers Swansea on Sunday, must wait to discover if they will host their League Two rivals Newport or second tier Blackburn.
If West Bromwich Albion manage to get past Bristol City in a replay they will welcome Peterborough, while Everton will visit either Carlisle or Yeovil.
Watford travel to Nottingham Forest and Bournemouth could enjoy a short trip to Fratton Park if local rivals Portsmouth can overcome Ipswich.
FA Cup Round 4 draw:
West Brom/Bristol City v Peterborough
Eastleigh/Bolton v Leeds
Arsenal v Burnley
Derby v Manchester United
Huddersfield/Reading v Walsall
Exeter/Liverpool v West Ham
Wycombe/Aston Villa v Manchester City
Shrewsbury v Sheffield Wednesday
Nottingham Forest v Watford
Carlisle/Yeovil v Everton
Crystal Palace v Stoke
Oxford v Newport County/Blackburn
Ipswich/Portsmouth v Bournemouth
Colchester v Tottenham/Leicester
Bury/Bradford v Hull
Northampton/Milton Keynes Dons v Chelsea
Ties to be played January 30/31