Lehmann believes he can cope if he adjusts quickly to the tempo and intensity of the Premier League.
“Per will have to get used to English football, particularly the speed of the game,” he said.
“It is faster than the Bundesliga and will be a change for him, but he will cope. I am absolutely sure about that.”
Lehmann and Mertesacker were in the German side that reached the semi-finals of the World Cup in 2006 and the goalkeeper has no hesitation in providing a glowing reference.
“The club will benefit from having him because he brings more quality to their defensive line-up. “