United finished the first leg against their German opposition with a 1-1 draw at Old Trafford, but are looking to come out on top at the Allianz Arena on Wednesday night.
Speaking on his official Facebook page, Rooney said:
"Good training session with the lads ahead of the Bayern Munich match tomorrow night. It's a massive game for us against a top side but we'll be going in confident and looking to progress into the semi-finals."
Rooney, whose corner set up Nemanja Vidic for the opener in the first leg, will be hoping the away goal Bayern currently have can be cancelled out in Germany.
David Moyes' men face a tough task against the holders Bayern, who overcame fellow Bundesliga club Borussia Dortmund to be crowned champions in May last year.
Moyes, who has been the subject of constant criticism since taking over from Sir Alex Ferguson as United manager in July 2013, will have taken a lot of positives from his team's performance against Bayern last week.
The Manchester club were extremely unfortunate to have Danny Welbeck's early strike ruled out by Spanish official Velasco Carballo for a raised foot on Javi Martinez.This decision did not dent United's determination though as they continued to press with a spirited performance.
This was a far cry from the United we have seen in the Premier League, who have given a disappointing title defence since the appointment of Moyes.
Moyes' side, who were knocked out of the Champions League by Real Madrid last season, will be looking to prove their worth against the Bundesliga title holders and progress to the semi-finals of the competition.
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