The 6ft 6ins centre-back has grown in stature at the heart of the Gunners rearguard alongside Laurent Koscielny this season, the duo helping secure another clean sheet in the 2-0 win over Marseille at the Emirates Stadium which put Arsenal within touching distance of the last 16 of the Champions League.
The 29-year-old admits it took him a while to settle following a switch from Werder Bremen on transfer deadline day in August 2011, with an ankle injury later ruling him out of Euro 2012.
Now, though, Mertesacker - who has become a cult favourite with Arsenal supporters - intends to make the most of his consistent form to help drive the Gunners on to success both in the Barclays Premier League and in Europe.
"The first year was tough for me, a very tough challenge, but the club and the manager always trusted me in a special way," said Mertesacker.
"I think it is a little reward that we are talking (about a new contract), because I still have one-and-a-half years left.
"There is no rush, but it seems that some people are delighted with my performances at the moment. I am pleased with the situation."
Mertesacker, whose headed goal gave Germany a 1-0 friendly win over England at Wembley during the international break, recalled: "I went through a lot of difficulties and a lot of mistakes at the beginning, but the manager always said I would get through it because I was a good player.
"I took my time to settle down completely and there were a lot of reasons.
"I missed completely the pre-season (before joining Arsenal), so it was really hard because I had to work straight away to play straight away.
"It took me a while to get to that level, but the manager always trusted me and said I was intelligent enough to cope with problems.
"Then I got a big injury in my first year and I missed Euro 2012, so I was fit for my second season.
"Maybe it was a good thing that I missed the competition with Germany to train and get my body fit."
Despite beating whipping boys Marseille to stay top of Group F, Arsenal are not yet mathematically certain of a place in the knockout stages following Borussia Dortmund's win over Napoli.
The Gunners head to Italy on matchday six, and anything other than a three-goal defeat would see them progress while a draw would secure top spot and with it seeding for the knockout stages.
Arsenal had raced ahead inside 30 seconds against Marseille through a fine run and finish from Jack Wilshere.
It should have been 2-0 before half-time, but Mesut Ozil's tame penalty was saved.
The German playmaker did, however, put the crucial second goal on a plate for Wilshere, who swept home a perfectly-weighted ball across the six-yard box on 65 minutes.
Midfielder Mikel Arteta feels that shows the mental strength of the club's record signing, who has been under some scrutiny in recent weeks following a few indifferent displays.
"Penalties are very decisive moments," he said. "Only a detail makes it go in or out. I don't think it's about confidence."
Arteta - who is Arsenal's usual penalty taker, but was on the bench until the final 10 minutes - wants the team to quickly refocus on Saturday's Premier League game at Cardiff.
"Cardiff will be very tough. That is why we need to get back and prepare well for Saturday to make sure we get the points again," he said.
Midfielder Mathieu Flamini, meanwhile, was criticised by Wenger for cutting the sleeves off his shirt, going against club tradition.
The 29-year-old has settled quickly since his return to Arsenal on a free transfer this summer.
"I am not really surprised (it has gone well) because the philosophy is still the same," said Flamini, who was back from a one-match suspension.
"We are still playing the same football. Arsene Wenger is still here with the same conviction, for me on the pitch it is always the same game so it went very naturally."
Source: PA
Source: PA