Sir Alex Ferguson accused his Manchester United players of becoming casual and risking an “embarrassing” anticlimax as they edged to a 2-0 victory over Portsmouth last night that took them three points clear of Liverpool at the top of the Barclays Premier League.

After Liverpool’s dramatic 4-4 draw at home to Arsenal 24 hours earlier, the United manager was frustrated to see his strongest available side — minus a “tired” Rio Ferdinand — come close to conceding home points of their own as they allowed Portsmouth back into a game in which they took an early lead through Wayne Rooney. Only when Michael Carrick scored eight minutes from time were the champions secure.

A side showing nine changes to the one knocked out of the FA Cup on Sunday homed in on a third successive league title — they have a game in hand on all their rivals — despite an unconvincing performance, although Ferguson claimed that only poor finishing had let them down initially.

“In the first half we played some of the best football you’ll see all season,” the United manager said. “The football was absolutely fantastic but we missed four or five clear chances. We could have been 5-0 up but, at only 1-0, we made it difficult for ourselves. We encouraged the opposition and I thought we were going to throw it away.”

It was not all good news for the champions, with United’s defensive resources being stretched ahead of their Champions League semi-final, first leg with Arsenal on Wednesday. Gary Neville limped off in the thirteenth minute and John O’Shea, his replacement, was also withdrawn, both with what are thought to be ankle injuries. “They’ll be out for weeks,” Ferguson said. The return of Wes Brown, who played for the reserves on Monday, is well timed.

Ferguson was adamant that his players will not be slacking off any more in the home straight. “We’re in a better position than we were yesterday morning,” he said. “But having seen that second half when we got so casual, I’m taking nothing for granted. We’ve got to keep our foot down all the time.”

While Paul Scholes was restored to the starting line-up for his 600th game for the club last night, sliding in the pass for Carrick’s goal, Carlos Tévez reverted to his customary place on the substitutes’ bench and he has admitted that he may leave Old Trafford when his two-year deal expires in the summer.

“Even if you score three of four goals, you do not play in another game,” the Argentina striker said. “There are many very good players here but I need to play. I have trained every day and never said anything against my team-mates or anyone, but it is true that there are other options for next season.”

Guus Hiddink conceded that Chelsea’s title hopes had all but evaporated after a 0-0 draw against Everton at Stamford Bridge that left them six points behind the leaders. “We said before that the two followers of Manchester United must not lose any points,” Hiddink, the interim manager, said. “But we lost two points and now we must be realistic.

“Mathematically there is still a chance, but I think we should follow the other two roads — the Champions League and Everton again [in the Cup Final on May 30]. We have West Ham on Saturday and we will not have the approach to let it slip away, but now we have to focus more on the Champions League games.”

As United regained pole position, one of their former players was dropping down a division. Roy Keane, who resigned from Sunderland in December. is expected to be named today as the manager of Ipswich Town, the Coca-Cola Championship club, who dismissed Jim Magilton yesterday.