Arsenal academy chief Per Mertesacker admits the squad has been addressed about being aware of their security.

Talks have taken place about the threat posed by gangs targeting footballers after Mesut Ozil and Sead Kolasinac had to fight off knife-wielding men, revealed Mertesacker.

"There was a big discussion around gangs in London and the security matters," Mertesacker said. "The major part of what car you drive, what you wear in terms of your jewelry. So you need to be risk-aware in those days that anything can happen at any time. And these are examples you are trying to avoid."

Concerns about their safety led to Ozil and Kolasinac missing games.

"Once these things happen," Mertesacker said, "it is an eye opener to where the world is in terms of poverty around London and how can we make sure that it is not going to happen again."