Arsenal defender Per Mertesacker says playing in the Premier League is the biggest challenge he's faced.

Mertesacker says he has enjoyed the challenge of moving from the Bundesliga to test himself in the Premier League.

"In general you are playing the best players in the world," he told Arsenal Player. "You always have to perform at a high level.

"It is at a constant level and that is what makes the Premier League so good and so sharp."