By Chris Harris

Arsène Wenger is used to hearing criticism of his new recruits but he insists Per Mertesacker is doing well - and will get much better.

The experienced Germany international was one of a clutch of signings in the final days of the transfer window and he has been thrown straight into the deep end with Thomas Vermaelen sidelined since he arrived.

Arsenal's defence - and by extension Mertesacker - has been questioned at times but Wenger believes the 26-year-old's intelligence and mental strength will shine through.

"He adapts quite well, he is getting more aggressive," said the manager. "I like him personally, I think he is a very intelligent player and he will be a big asset for us.

"I don't know if he realised how quick it [the football in England] would be but he has said it's quick - relentless! But trust the Germans, they can fight.

"New signings get judged very quickly but if the team doesn't win then nobody is good - it is like that. The players who are mentally strong - and I think Per is - will get over that. I'm happy with what I see from him.

"Many times you know people judge your buys quickly but personally I am happy with the buys we have made. I'm not happy with the results we have made - that is completely different. I have heard that Song is a bad buy, that Henry is a bad buy, but over time they have been alright."

When Wenger arrived at Highbury in 1996 he was handed some of the Premier League's finest - and most vocal - defenders on a plate. Tony Adams, Steve Bould, Martin Keown, Lee Dixon and Nigel Winterburn were all at the club but their old manager rejects claims that he has not or cannot build a defence.

"I inherited a fantastic defence but what people forget is that it was not the unbeatable ['Invincibles'] defence, it was not the best defence," he pointed out.

"People say we never had to build a defence but that defence with Lauren, Sol Campbell, Kolo Toure and Ashley Cole was the unbeatable one. The four defenders we had were talkers as well.

"We have had quieter defenders recently but I think Mertesacker can be a talker. He will come out of himself, don't worry."

Copyright 2014 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source 15 Oct 2011