The 19-year-old moved to the Emirates for £16m last month and has impressed during the early stages of his Gunners career.
"I'm just trying to take Calum under my wing and show him the ropes. He's a really good lad and everyone really likes him - the boys really want to go out of their way to help him bed in," he told the club's official website.
"We saw him play for Arsenal for the first time at the Emirates Cup and I thought he was superb for a 19-year-old playing centre-back against really good players. I thought he looked very assured and he's going to be a great talent for the club."
Arsenal open their Premier League campaign away to Crystal Palace on Saturday.