Rafael Benitez believes Liverpool's trophy chances will be virtually decided in a four-game run crammed into only 10 days.

Liverpool face Manchester City at Anfield on Sunday and then travel to Spain to face Real Madrid in the Champions League on Wednesday.

Next Saturday they are at Middlesbrough in the league before facing Sunderland at home on March 3, a game that has been rescheduled for TV.

With Manchester United producing a relentless winning run at the top of the Barclays Premier League, the Liverpool boss conceded there can be no slip-ups during the next vital spell of the season.

And he may have to embark on this testing programme without captain Steven Gerrard for two of those four games.

Gerrard has not recovered quickly enough from a hamstring injury to figure against Mark Hughes' side on Sunday, and a decision will be taken as early as Monday by club doctors on whether Gerrard can lead the side in the Bernabeu.

The fact Benitez will make such a decision 48 hours before the match suggests Gerrard is a doubt already, despite the Spaniard insisting his key midfielder "is positive about playing in Madrid".

But it is the virtual admittance Liverpool dare not drop a point in their next three league games that underlines the importance of the next few days to the club's entire season.

United's stunning form has clearly forced Benitez to view these next games in such a way, with Sir Alex Ferguson's side already five points clear at the top - which could be an eight-point margin if the champions beat Blackburn tomorrow at Old Trafford.

Benitez said: "This is a crucial time, we have four games in a few days and that can make a massive difference to whether we will be fighting for trophies at the end of the season.

"At this stage, you can only think of taking three points and then seeing how your rivals do.

We cannot influence what happens to other teams so we must concentrate on our own job and see whether someone else loses a match or two.

"It is not just us and Manchester United, Aston Villa still have an interest and so do Chelsea."

He added: "It now depends on one or two weeks to see what happens. Everything can change in just a few days.

"Manchester United are a good team, they are winning many games in a row, so we know we have to win almost every game. You cannot even draw a game at the moment.

"If we can beat Manchester City it will give us confidence, every game now at this stage can affect the mood in the dressing room."

Benitez, who will also be without the suspended Xabi Alonso against City, continued: "We have four games very quickly now, and there is not time to rest players and recover.

"But we must win these games because United could still continue winning, too. That will then make our game at Old Trafford next month crucial."

He added: "Five points is a significant lead. But it is not impossible. If we win our games before we go to Old Trafford, and then we win, the gap will be just two and then we will wait to see how that affects the situation.

"We can win without (Fernando) Torres, we can win without Gerrard, but it is easier to win with them both playing.

"It does not matter what other teams say about us being challengers or not, we just have to do our job and win our games.

"Manchester City have a poor away record but teams come to Anfield wanting to show what they can do. It is a window for them, so you cannot really make assessments based on form, just on the quality of players they have."