Sir Alex says there's no guarantee the Reds' domestic challenge will get easier now.
"It's not a sense of relief [going out of Europe] because we still have 10 games to play [in the league] and that's a long way to go until you can win a title.
"Obviously we now have to make sure we win on Sunday against Wolverhampton Wanderers. We decided to take off Rio Ferdinand, Michael Carrick and, eventually, Ryan Giggs because we have to think about Sunday."
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