United's Title Defence

After a season of injury bedevilment in defence, Sir Alex Ferguson suspects having a consistent back four for the remainder of the season can make the difference as United hunt a fourth straight Premier League title.

A third clean sheet in eight days against Fulham signified a return to the unflinching form which underpinned last season's triumph. With Nemanja Vidic and Rio Ferdinand back in tandem and flanked by Patrice Evra and Gary Neville, Sir Alex feels keeping those four fit - and maintaining the availability of understudies Jonny Evans and Rafael - is key as United look to close out the season in style.

"I think the key for us is if we can keep the back four in together," he told MUTV. "We've had a few injuries, particularly to defenders. I keep praying. If we can keep that back four together, with the experience they've got, and van der Sar's experience at the back, that'll give us a massive chance.

"Jonny Evans and Rafael missed today; Rafa got injured in training and Jonny felt his knee, and we can't take risks with defenders at the moment. We have to have someone ready for the next game, and both of them will be ready for next Sunday (against Liverpool), for instance.

"So that's the situation we're in at the moment. John O'Shea will hopefully be back for the beginning of April, he's looking much better now. Young Fabio made his return today after a few weeks out with an injury, so it's a patching up job almost every week, getting defenders ready."

The champions currently boast the meanest defensive record of the Premier League's top three, despite this season's spate of injuries, with just 24 goals conceded.

Rooney (right) took his tally to 24 Premier League goals on Sunday. The reigning Champions will next face Liverpool at home on 21st March.