The 27-year-old, who is currently sidelined with an ankle injury, joined the Gunners from Werder Bremen last summer but struggled to adjust his game to the fast pace of the English game.
However, the German now feels settled, declaring that he relishes facing some of the best players in the world in the Premier League.
"Sometimes I felt like it was very hard, especially when I first came here," he told Arsenal's official website. "It was tough to settle down [and I was] very quickly into the first-team squad.
|GUNNERS BLAST THROUGH?|
|7/2||Arsenal are 7/2 with William Hill to be drawing at half-time and leading at full-time against West Brom|
"In general you are playing the best players in the world. 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."
Mertesacker has made 21 appearances in the league this season but faces a race to be fit in time to take his place in his Germany’s squad for the upcoming Euro 2012 in Poland and Ukraine.