Former Arsenal stopper Jens Lehmann has backed compatriot Per Mertesacker to be a success at the Emirates.
The 41-year-old keeper, who returned to the Gunners for a brief second-spell in March last season, enjoyed a more successful five-year spell under Arsene Wenger between 2003 and 2008.
Despite a recent downturn in fortunes, Lehmann believes fans should be optimistic by the arrival of the German centre back, who has 75 caps to his name at international level and joined from Werder Bremen.
"There is no doubt in my mind that he will be a huge success for Arsenal," Lehmann told the Sunday Mirror.
"He will be a great support for Arsenal. It was a very good decision to sign him - good for Arsenal and for Per.
"The club will benefit from having him because he brings more quality to their defensive line-up."
A renowned problem position in recent seasons, Mertesacker and Brazilian international Andre Santos have added both quality and depth in the area for Wenger.
The pair are likely to get their first chance to shine for the north Londoners this weekend, when Swansea City travel to the Emirates.