Sir Alex Ferguson has underlined his determination to ensure Manchester United are still rated alongside the likes of Barcelona as they prepare for a "very difficult" trip to Valencia.
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United, three-time champions of Europe, last reached the final in 2009, but Ferguson has spoken repeatedly of his frustration at the quarter-final exit to Bayern Munich last time around.
With Cristiano Ronaldo and Carlos Tevez having left after the final defeat to Barcelona in Rome, United may feel they still have something to prove in the competition, and Ferguson is looking to make sure their status does not slip.
"The Champions League is the best tournament," he said. "It's the biggest challenge, because you're playing the best teams. You want to be classed alongside the likes of Barcelona, the great teams who've won it so many times.
"There's a big expectation for us to do well in Europe. Sometimes we've disappointed and sometimes you can be unlucky - one bad moment in football and you can go out - but it drives you on and hopefully this year we can do better."
United suffered a disappointing 0-0 draw at home to Scottish champions Rangers in their opening group game in the competition this season, and it could prove difficult to get their campaign back underway in their second game as they travel to in-form Valencia.
"It was a disappointing result for us in the first game but we have five games left to qualify," he said.
"We expect a very difficult game. Valencia are top of the league. I watched them last Wednesday, and on TV on Sunday, and they're playing very well.
"Spain is obviously the hardest place for us to go. Spain has produced cup-winning teams for years and years - you have to recognise that. The standard of Spanish football has always been very good, so it will be a tough game. We're all aware of that."
"Rio is much fitter now," he said. "He has had plenty of training, a couple of reserve games and matches against Rangers and Scunthorpe.
"He was out for five months so he still probably needs another game or so, but the important thing is he is coming back and we look forward to having him back."