Manchester United manager Sir Alex Ferguson has warned his players not to under-estimate AS Roma ahead of their Champions League quarter-final second leg.
United are firm favourites to reach the semi-finals after securing a 2-0 first-leg advantage in Italy last week.
However, Ferguson has warned his players not to take their progress to a potential last four meeting with Spanish giants Barcelona for granted.
He said: "We have one foot in the semi-final and the clock is against Roma, but nothing is certain in football. You cannot take anything for granted.
"We have been involved with Roma a lot recently and I do not think they will change anything in their approach to this match.
"We have to counter any danger. When you are at home you have to express your performance in a big way and hopefully we can do that."
Meanwhile, Ferguson has played down claims that his side is currently the best in Europe.
"I watch games in Europe and see different types of football," he continued.
"That makes it difficult to assess where we are. The best way to assess it is if we get to the final.
"You can be the best team and lose. That's why we are not in the FA Cup final.
"We are looking for consistency. If we can get it in Europe, like we have at home, then we have a chance."
The Red Devils will give Rio Ferdinand every opportunity to prove his fitness after he suffered a foot injury during Sunday's 2-2 draw with Middlesbrough.
The England defender will have a fitness test at United's Carrington training ground on Wednesday morning, with either Gary Neville or Mikael Silvestre ready to deputise if required.