With incumbent central defenders Neven Subotic and Mats Hummels still at the Westfalenstadion, he may face a battle earning a place in the starting line-up.
But, after enduring a frustrating year at AC Milan where he rarely played, Papastathopoulos is determined to force his way into the first XI after inking a five-year deal with the German giants.
"I came here to play, like every other player. It's normal," Papastathopoulos said.
"I left AC Milan because I wasn't playing, then I moved to Bremen where I played a lot and now I'm here to play. I believe every player joining a team wants to play.
"Things with the other players are going well. I'll play where the coach needs me, if he wants me to play right back or as a centre-back I'll do it."
Dortmund will be looking to patch up their leaky defence in season 2013-14.
After conceding just 47 goals across their title-winning seasons of 2010-11 and 2011-12, Juergen Klopp's men allowed 42 goals last season alone.
Papastathopoulos knows first-hand the value of a solid defence after seeing his former team Werder Bremen leak 66 last term - second only to Hoffenheim (67).
"In Bremen every year the team had a problem in defence because everyone wanted to attack and it's difficult to defend," the Greek international said.
"That was my old team, now I'm in a new team, one of the best ones, we need to be perfect in defence."
