The Dane feels their 2-2 draw at Borussia Monchengladbach was the ideal preparation for the clash.
The 23-year-old admitted it was "special" to return to Borussia-Park where he played on-loan for two seasons, but now his focus is on final preparations before they begin their league campaign with a tasty fixture at Old Trafford.
He told the club's website, "We are going into the Premier League with a good feeling. We want to be where we have to be. We are going to be ready. Pre-season is always hard. We have had some difficult games and this was a good test for us.
"It's going to be very difficult on Sunday. We still need a bit more but we have a week to prepare. It's going to be very tough, especially away, but I am sure we will be ready."