In an apparent attempted carjacking caught on camera in July, Kolasinac jumped out of a vehicle to confront masked aggressors, who had pulled alongside the vehicle on mopeds. A separate incident led to two men being charged with a public order offense outside Ozil's house in north London.
"There was a big discussion around gangs in London and the security matters," Mertesacker told The Associated Press. "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."
Especially as Mertesacker, the Arsenal captain before assuming the academy role two years ago, does not want players to become even more distant from fans. "When these things happen, the more fences, the more security guys and the more gates will eventually happen," Mertesacker said. "And that would be very, very sad."
In an interview promoting the launch of his autobiography "Big Friendly German," Mertesacker also addressed Arsenal's quest to return to the Champions League as the team prepares for the third consecutive campaign in the Europa League.
"That is our target this season, there is no doubt about it," Mertesacker said. "If you speak in timeframes — two or three years, that is (Arsenal) competing for the Premier League title." That has not been achieved since 2004. Unai Emery's second season in charge has opened with Arsenal collecting seven points out of a possible 12 despite the manager adding Nicolas Pepe in the offseason to lead the attack with Alexandre Lacazette and Pierre-Emerick Aubameyang.
"I think we have a lack of balance right now," Mertesacker said. "Where you feel like, OK we have amazing strikers but that as well need to understand that we need to have a certain compactness. So it's not only about us three (lead) strikers providing an offensive threat. It is about these front three as well, leading the first frontline as being a defensive unit.
"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. So it's not only the back four who should be judged on how many goals we concede."
Although inevitably there will be focus on David Luiz's contribution. The summer central defensive recruit from Chelsea has had an uneasy start to his Arsenal career, accepting blame for goals being conceded.
"I think he will learn from his mistakes on the pitch, but he is very comfortable being at Arsenal," Mertesacker said. "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."
More AP soccer: https://apnews.com/apf-Soccer and https://twitter.com/AP_Sports