United back in Liverpool for tense cup clash
Manchester United manager Sir Alex Ferguson has called on fans and players to act responsibly when his team go to Anfield for their first match against Liverpool since Luis Suarez was banned for racially abusing United defender Patrice Evra in October.
Ferguson has written to United's fans asking them to behave and called for full co-operation between fans, stewards and police at Sunday's game.
On the pitch, his main worries concern Nani, who will miss the game, Phil Jones, Anderson, Ashley Young and Wayne Rooney.
Liverpool Managing Director Ian Ayre wants "rivalry not hatred" on Saturday, saying: "We mustn't detract from fans chanting and singing at each other but it needs to be a rivalry thing rather than a hatred thing."
Manager Kenny Dalglish has no major injury worries though Jay Spearing is still suffering with a hamstring injury and is a doubt.
Sunday's match between Queens Park Rangers and Chelsea at Loftus Road is also over-shadowed by a racism row sparked when they met in the League in October and Chelsea skipper John Terry allegedly racially insulted QPR defender Anton Ferdinand.
Ferdinand has not yet decided whether he will shake hands with Terry before kick-off.
New QPR manager Mark Hughes must decide whether to give debuts to Nedum Onuoha, who joined the club from Manchester City this week, and Taye Taiwo, who arrived from AC Milan.
Chelsea are likely to be without Frank Lampard who injured his hamstring against Norwich City last week. The match comes four days before Terry is due in court to answer the racism charge, which he has denied.
Arsenal manager Arsene Wenger will be hoping Mikel Arteta has recovered from calf and shin injuries and that Thierry Henry (calf strain), will also be fit in time to face Aston Villa at Emirates Stadium on Sunday.
Wenger said on Friday that Jack Wilshere, who has been out all season with an ankle injury, had suffered a minor setback in his recovery and was going for tests. Wilshere had been pencilled in for a mid-February return.
Aston Villa boss Alex McLeish will be without midfielder Charles N'Zogbia, who has a heel injury, but will be hoping Steven Ireland and Gabriel Agbonlahor play after a hamstring injury and illness respectively.
Newcastle United, who won the last of their six FA Cups in 1955, travel to Championship Brighton on Saturday looking to put last week's 5-2 hammering at Fulham behind them.
The main worry for coach Alan Pardew is whether defender Fabio Coloccini recovers from a knock in time to play on the south coast in their first FA Cup meeting since 1986 when Brighton beat Newcastle 2-0 in a third-round match at St James' Park.
Stoke City, last season's beaten finalists, renew their old rivalry with Derby County of the Championship on Saturday.