Arsenal boss Wenger: Mertesacker now dominant force for our club
The Germany defender is showing why Wenger brought him to the club last year.
The Frenchman said: "Per is becoming a dominant force for our club.
"He is a recognised centre-back in this country and he has a leading role in our team.
"Yes, it took him a while to get to this point - but I can honestly see that he has improved in terms of his mobility, his technical ability and also his personality."