The game against Chelsea in the Champions League on Tuesday (November 25) marks the first time Rashford, 28, will face an English club since joining Barcelona in the summer.
Rashford was a doubt for the game at Stamford Bridge due to injury, but it has since been confirmed he will be fit and able to play.
Speaking ahead of the game, Flick was full of praise for the England international, saying: “I’m really very happy. He came back from a cold, but he’s OK. We’ll decide tomorrow if he starts or not. But I’m happy to have him in our team.
“I followed him his whole career, I was impressed with his quality, what he’s doing in the box in front of the opponent’s goal. He has shown it in Barcelona.
“Also for him this change to live in another culture, with fantastic people, nice weather, it’s amazing. We can see now he’s also smiling a lot. If he can enjoy the atmosphere we have it’s also very good.”