Arsenal defender Per Mertesacker says he has relished the challenge of playing in the Barclays Premier League this season. The Germany international has not featured for the Gunners since damaging his ankle in the 2-1 win against Sunderland on February 11th. But he was a regular before the injury and, as he continues his recovery, the 27-year-old said he had been impressed with the quality of the League. “In general…