Former Arsenal defender Per Mertesacker is confident that new signing David Luiz will learn from the mistakes he has made in the last two games, and said that the Brazilian brings something different to the table.

Luiz was signed by Arsenal in the final hours of the English transfer window, with the Gunners paying Chelsea £8million for the 32-year-old’s services. The Brazilian is expected to help an ailing defence that just lost their best defender in Laurent Koscielny.

However, Luiz has had a couple of high profile games in which he did not do all that well, but Mertesacker is confident that he will learn from his mistakes.

"I think he will learn from his mistakes on the pitch, but he is very comfortable being at Arsenal," Mertesacker told Sky Sports, according to Goal. "That's what I have been seeing. So we are happy to have him. He brings something different to the table right now. So I think he is able to learn and excel his level of being an Arsenal player."

The Gunners’ academy manager also touched on the fact that Arsenal seem to be top heavy, and cautioned that the team also needs some defensive compactness.

"I think we have a lack of balance right now, where you feel like, OK we have amazing strikers but they as well need to understand that we need to have a certain compactness," Mertesacker said. "So I think we need to be cautious of that. No matter how much striking power you have got, you need to have a sense of defensive compactness from everyone."