Rooney is a key figure for United, who have Javier Hernandez and Dimitar Berbatov out injured, in what is a massive fixture for the team, with a point needed to qualify for the knockout stages of the competition.
On Thursday, he will find out whether his three-match ban for kicking an opponent during England’s qualifier against Montenegro will be reduced which would let him play a greater part in Euro 2012.
But his club manager says any thoughts about the appeal will not be in his mind when he steps on to the pitch to take on the Swiss side.
"I don't think that comes into it at all," Sir Alex told reporters when asked if the hearing was likely to affect Rooney's focus. "He has a game tomorrow. An important game."
United go into the match hoping not to repeat their performance six years ago where they lost in Portugal to Benfica and crashed out at the group stages.
However, Sir Alex is confident that history will not repeat itself once again.
"The side that played then was a very young team that suffered with a lot of injuries," he said.
"That period was disappointing. But it is six years ago. Our record since then has been outstanding.
"People say we are not doing well but we are second in the league and we are at a stage where we could be qualifying for the next phase of the Champions League. The pressure won't affect us.
"Look at the number of big games these players play in. Every year for the last few years they have been involved in finals and semi-finals and quarter-finals and big games in the Premier League.
"Wednesday is exactly the same situation. It is another big game. But we have a strong squad and that squad will see us through without question."
How do you stay up to date with football when on the move? With http://m.goal.com – your best source for mobile coverage of the beautiful game.