Ferguson praises van Persie ahead of Liverpool clash
Van Persie has netted 16 league goals to help United open up a seven-point lead at the top of the Premier League table since joining from Arsenal in a £24 million ($38.7 million, 29.1 million euros) deal in August.
Despite Liverpool's stuttering league campaign, Suarez heads for Old Trafford only one goal behind van Persie in the Premier League scoring chart, but Ferguson says his players will not afford him special treatment.
"We pay respect to every opponent we meet and the analysis and assessment of our opponents is always important," United manager Ferguson told a news conference on Friday.
"Suarez is no different to any other good player that we come up against in the league."
Uruguay international Suarez was banned by the Football Asociation for eight matches for racially abusing United full-back Patrice Evra during a game at Anfield in October 2011.
But the pair put their past problems to one side to shake hands when the two teams met at Anfield last September, after Suarez was criticised for failing to shake the Frenchman's hand prior to a match in February last year.
The topic was not raised at Ferguson's pre-match news conference, which was instead dominated by questions about the fine form of van Persie.
The United manager said: "I expected him to be an important signing for us but you never really know for certain what you're going to get.
"What we're finding is that any player coming here for the first year, you never know for sure. Who would have thought that Wayne Rooney on his debut would have scored a hat-trick (against Fenerbahce in 2004)?
"It's fairty-tale stuff. To pay that amount was a lot of money but we wanted him (van Persie) badly so we were prepared to go that extra mile for him.
"It's just the way the game is nowadays."
Ferguson said Rooney would not be available for Sunday's match, although the England international may face West Ham United in an FA Cup replay next Wednesday.
Rooney was set to return to training on Friday after a knee injury, while Nani and Anderson have been added to the squad after overcoming injuries.
"It's the Liverpool derby game," said Ferguson.
"It never changes. It's always an immensely important game and also intense and emotional -- everything you can think of in a derby game will probably be there on Sunday."
"There's nothing to report, I can tell you that," he said.
"It's January, for goodness' sake. There's no story to tell you."
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