Sir Alex Ferguson briefly dared yesterday to look ahead to what could be an enthralling Champions League semi-final against Barcelona, but the Manchester United manager urged his players to finish the job against AS Roma at Old Trafford this evening before allowing themselves to drift into such reverie.

With United 2-0 up from the first leg in Rome, Ferguson will make changes this evening, with Gerard Piqué on standby to replace Rio Ferdinand, Mikaël Silvestre in line for his first appearance since September and Gary Neville pencilled in for his first outing in 13 months. But he insisted that there can be no complacency among his players as they look to justify their status as favourites to lift the European Cup.

“Let’s be sensible,” Ferguson said. “We’ve got one foot in the semi-final and the best way to get two feet in is to approach the game in a proper fashion and go and win it. We can’t look upon the performance in Rome as a pass into the semi-final.

“We got there because we worked our socks off, because the team discipline was very good, because tactically we were very good on the night, and that’s the performance we need again. The sensible approach is for us to wait until after the game against Roma and then hopefully we can start to dream.”

With Roma again having to cope without Francesco Totti, their inspirational captain, bookmakers were offering odds as short as 1-40 on United reaching the semi-finals and, given that Ferguson’s team have won their past ten home matches in the tournament, those odds appear justified.

United, however, will probably be without their two first-choice central defenders, with Nemanja Vidic sidelined by a knee injury and Ferdinand rated as unlikely to pass a fitness test on his bruised left foot. “I’m obviously hoping Rio can play,” Ferguson said yesterday. “He will have to do something [in terms of training] in the morning if that is to be the case.”

Piqué, the 21-year-old Spanish defender, is expected to deputise for Ferdinand, while Silvestre may return at left back, with Patrice Evra one yellow card from suspension. Ferguson also hopes to welcome back Neville, who has had a torrid time since damaging ankle ligaments, but the 33-year-old is likely to be kept on the bench until the tie is safe.

Ferguson said that he does not know whether United are the best team in Europe and that they would need to win the Champions League — or at least reach the final — if they are to prove that they are. “In football you can be the best team and lose,” he said. “That’s why we’re not in the FA Cup Final. Hopefully we can produce the performances that get us to the final. But if we get past this one, we’ll face Barcelona [who begin their second leg at home to Schalke 04 leading 1-0], a marvellous football club with a great team, which shows you these things are never easy.”

Park Ji Sung, who sat alongside Ferguson during yesterday’s press conference, was asked only one question, but the South Korea midfield player did come up with the answer that perhaps encapsulated United’s confidence. Asked whether he thought that they could lift the European Cup, Park said: “Yes. We can win the double.”

As Ferguson no doubt warned him as they left the room, they could end up empty-handed if they get too far ahead of themselves.