Christensen, who is midway through a two year loan at Gladbach, reckons the 23-year-old will make an impact at Emirates.
"He has got a big personality, he is great in the dressing room and he is a really confident guy. He plays with a lot of emotion, I think if he can adapt to the English culture, he will be great.
"As a person he can be determined, focused and funny, but he is fun and a nice lad so he is kind of the same as he is on the pitch. He has got a lot of emotions [when he plays] and he just wants to win.
"He is like that outside the pitch as well, he is a good person to have around, he will be good in the Arsenal dressing room. I will text him before the game comes around. It is not that far away!"