Suarez at Messi/Ronaldo level, says Rooney
Liverpool's Luis Suarez breaks clear with the ball to score his team's fourth goal during the English Premier League football match against Everton at Anfield stadium in northwest England, on January 28, 2014 - by Paul Ellis
Liverpool approach the match at Old Trafford with an 11-point lead over their old rivals and Suarez has been a key factor, scoring 24 of the 73 goals that Brendan Rodgers's side have plundered this season.
Suarez has formed an impressive understanding with Daniel Sturridge, who is Rooney's strike partner at international level, and the United striker feels that the Uruguayan now merits comparison with the very best.
"Suarez, for me, is up there with Lionel Messi and Cristiano Ronaldo as one of the best players in the world," Rooney told United's in-house television station, MUTV.
"He has been that good and the two of them together have been in great form this season. We will have to do everything we can to stop them on Sunday.
"I think they are both fantastic players and obviously it is good to see Sturridge doing well because he has never really had a chance at his previous clubs.
"Brendan Rodgers has given him a chance and he has taken it with both hands. That is good for England as well."
While Sturridge has contributed 18 goals to Liverpool's league-leading tally, Rooney and Van Persie have found the net only 11 times each in the league this season.
Both players have had to contend with injuries, but they are now fit, and having each committed their futures to the club, Rooney is hopeful that the goals will soon begin to flow.
"We can do better and if we are not at the top of the league then that will get looked at, and we understand that," he said.
"We can score more goals and we know we can. We are working hard to do that, we have to keep going and hopefully that will come."
- Rodgers sounds warning -
United, the defending English champions, face an uphill battle to qualify for next season's Champions League, having fallen nine points below fourth-place Manchester City, who have two games in hand.
Not since 1995 have United failed to qualify for Europe's premier club competition and Rodgers feels that missing out on next season's tournament could have long-lasting ramifications for David Moyes's side.
"We still have a lot of work to get in to the Champions League," said the Liverpool manager, according to reports in several British national newspapers on Saturday.
"But when you're not in it, even though this club is a worldwide, monumental club, we found it difficult because the best players want to play in the best competitions.
"This was Liverpool and we weren't in the Champions League. In order to get in some of the type of players we want, that's where we need to be and we're trying to be.
"Any club will suffer the same when they're not in there. There is no doubt it will hurt you, but they (United) will know that."
Liverpool, English football's dominant force in the 1970s and 1980s, have not won a league title since 1990 and Rodgers has warned United that their own period of dominance could end just as abruptly.
"We were talking about the great Liverpool teams -- one year becomes two and then all of a sudden it was 20 years since they won the title," said the Northern Irishman, whose side went into the weekend in second place in the league table. "It can get away from you very quickly."