The 19-year-old has partnered both Mertesacker and Laurent Koscielny during the early weeks of his Arsenal career and has been rewarded for his eye-catching displays with a call-up to the England squad.
Mertesacker has been impressed by Chambers' attitude and will offer guidance to the young defender on how to find the right balance between the domestic and international game.
"A first proper pro season at a Champions League club and [playing] international football will be very tough mentally and physically," Mertesacker said. "But he has the character to cope with it. If he wants any advice, I'm here to help.
As a person I like him very much because he's calm, he tries to learn and he listens all the time and that is something that is really rare
"It's very important to have such ambitious players and you could feel that from the start when we first met just how ambitious he is and how important he is for the squad even though he is just 19.
"In our days, good players come in very early and they will get a call-up very early so I think it's down to the English manager and Arsène Wenger to deal with that. But his character is up for it. That's my opinion and I don't think it will go wrong for him.
"He will be very important for the club over the next few years. I didn't see him much last year for Southampton and I didn't recognise him. But how he managed to deal with the first few games under pressure and how he trains impresses a me a lot."
Chambers has featured predominantly in the heart of defence since he joined the club but can also play at right back and in central midfield. Mertesacker believes that versatility is an important attribute in a modern-day defender.
"He has everything," said Mertesacker. "He can play different roles and he will be very important. He comes in and it's easy for him to feel comfortable. He's so composed and he will play a big role. As a person I like him very much because he's calm, he tries to learn and he listens all the time and that is something that is really rare."Copyright 2016 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