Borussia Dortmund coach Jurgen Klopp has admitted that he's surprised Real Madrid sold Mesut Ozil to Arsenal.
Klopp, whose side will take on the Gunners in this year's Champions League group stages, has backed the opinion of Germany head-coach Joachim Low, who also believes Ozil's Madrid departure was a strange one.
When discussing Ozil's move to north London, Klopp told reporters: "I do not care which player will play against us in the UEFA Champions League.
"But Mesut is a football grenade. No one really knows why he was sold. Maybe Real Madrid needed the money?"
The 46-year-old manager believes Real's signing of Tottenham star Gareth Bale could have impacted the departure of the German international from the Bernabeu.
Klopp continued by saying: "Real Madrid chairman Florentino Perez wanted to have Gareth Bale, of course, and he paid 100million Euros.
"Florentino Perez once even bought Hochtief (the German construction company). Maybe he just doesn't know in the mornings what he is about to do with his money when the evening comes."
Klopp will be hoping to take Dortmund one step further in this year's Champions League as his side were beaten by German rivals Bayern Munich in the final in 2012/13.
Dortmund will first face the Gunners on October 22 at the Emirates, with the return game a couple of weeks later in Germany.
The north London outfit will be hoping to go further in this year's competition after losing to eventual winners Bayern in the round of 16 in the last-term.