The Frenchman expects his side to recover in time for the Champions League match against AC Milan on Wednesday.
Wenger, who was short on numbers due to injuries, insisted: "I am not worried about picking the players up for the Milan game.
"It is massive match and we have to bounce back quickly from our disappointment. We will need to be at our best.
"The players have given me so much recently but unfortunately we were not up to the level required against United.
"At least we did not suffer any more injuries, so we might be able to find 16 players to face Milan."
Arsenal are five points clear of United at the top of the table but you would never have guessed it as they were outplayed from start to finish.
But Wenger claims it will be different when they meet again in the league in April.
He said: "I believe this result is a one-off. We will come back to Old Trafford in better shape and hopefully on a better pitch.
"The pitch is a disgrace. You have players worth £20-25million and you cannot play a pass without it bouncing."