Sir Alex Ferguson insists his players understand the need for rotation at Manchester United even if they do not accept it.

Ferguson dropped Carlos Tevez to the bench for Sunday's draw at Chelsea and Jonny Evans is bracing himself for the axe against Bolton on Saturday as Nemanja Vidic returns from suspension.

There is also a possibility Wayne Rooney or Dimitar Berbatov could be left out at Old Trafford as Ferguson tries to spread the load across his vast squad.

"If you want to make sure you win something, you need a strong squad," said Ferguson.

"That has paid dividends for this club, and others who have the same mentality.

"The players understand it when they are left out from time to time but it doesn't mean they accept it.

"They might do three days afterwards or three days before. They might know it has to be done and understand the mechanics of it.

"But they don't like it. I don't mind that.

"I would rather that than players who are quite happy to sit on the bench."

Ferguson has a big squad to choose from as well given only Michael Carrick and goalkeeping duo Tomasz Kuszczak and Ben Foster are missing from his senior men.

Rodrigo Possebon is absent too, although the damage to the young Brazilian's leg is nowhere near as bad as Ferguson feared when Emanuel Pogatetz thundered into him during Tuesday's Carling Cup win over Middlesbrough.

"We are delighted it is not more serious," said the Red Devils chief.

"At the time I feared the worst.

"I looked at the reaction from Nani when it happened. It was the same as the Arsenal players for Eduardo last season and even when (former Coventry defender) David Busst suffered his terrible injury at Old Trafford a few years back.

"There is no break and no ligament damage. It is just a gash in the bone.

"He does have to go back into hospital to have it closed up but we are quite happy with that."

Following public apologies from Pogatetz and Boro boss Gareth Southgate, Ferguson has declared the matter closed, although he does recognise referees have a major problem dealing with such incidents given the ferocity with which such tackles are made.

"There is nothing wrong with good tackling, it should be an art," said the Scot.

"Tackling should not be lost to the game.

"But the speed of tackling today has increased. When people go charging in and you get a slight error of judgement, you get bad tackles."

Not that Ferguson has any problem with his own side's competitive spirit despite the fact they picked up an incredible seven bookings at Chelsea.

"I maintain there was not one bad tackle in the match," said Ferguson.

"I have no problem with the discipline of our team. We always try to play football. Long may that continue."

After encouraging performances against Villarreal and Chelsea, followed by the win over Boro, United are in confident mood, even if they are still entrenched in the bottom half of the table.

They still have a game in hand against Fulham, although, on the eye of United's first home league game since the opening weekend of the season, Ferguson knows the Red Devils need to start winning.

"The win on Tuesday has sent us on our way," said Ferguson.

"It has been a tough start to the season with a run of away games at Portsmouth, Liverpool and Chelsea.

"But we have ended up with exactly the same number of points from those games as we got last season.

"It is early season of course. Nothing emphatic happens at this stage.

"But I expect our form to pick up now."