Sokratis Papastathopoulos has joined Arsenal from Borussia Dortmund “He’s a little obsessed with defending. He wants to protect the goal-line no matter what and he’s hungry to face duels,” Thomas Tuchel, his former manager said.Mats Hummels, his former partner in the Dortmund back line said: “The defensive work that Sokratis puts in is just unbelievable.”Have a look at some of his best tackles, courtesy of the Bundesliga YouTube channel, including the one where he stops Robert Lewandowski in his tracks.In signing the Greece international, it appears Arsenal have a leader in the team and someone vocal enough to let people know if they aren’t pulling their weight.This is what he said about Ousmane Dembele when the young France international was desperately pushing for a move to Barcelona.“Ousmane has given us a lot, he can make the difference in games. We need players like that. But we also need players who don’t step over the line and want to be part of our family,” he said. “He must understand that no player is bigger than the team. Everyone has to understand that they work for the team and have to fit in with that.”It looks like the Gunners have what they have been missing for some time.Papastathopoulos is the club’s third summer signing. 1 Arsenal confirmed they have signed Greek colossus Sokratis Papastathopoulos from Borussia Dortmund.The centre-back has ended five years at the Bundesliga club where he very little gets past him.