Heaven, now 19, had spent most of his youth career playing as a deep-lying midfielder before Per Mertesacker, then Arsenal's academy manager, first saw him play and became convinced he needed to be moved into the back line.
The decision proved decisive, ultimately earning Heaven a reputation as a defender that paved the way for his move to Manchester United. Lisa Heaven, who is also her son's agent, initially pushed back hard against the switch.
"I remember the conversation, it was between myself and Per Mertesacker," she told the Stretford Paddock. "I was having a debate with Per like, 'he's not a defender.'
"He was saying he was and I was saying he wasn't. I remember it was one of his first couple of games, and it was Per's first season as the academy manager.
"Ayden made a save off the line and I saw Per's face light up. I thought, 'He's not a defender. He's scoring goals.'"
Mertesacker was undeterred, according to Lisa, dismissing suggestions that her son should remain further forward.
"I think he was playing as a No6 and No8 role, really box-to-box. Per wasn't having it," she said. "He was like, 'He is a great player, but he is going to be a defender.'"
Heaven soon switched to the back line and quickly established himself as one of the country's top-rated young defensive prospects, though the change came relatively late in his development. He had played just one full season at centre-back before Manchester United moved to sign him.
"When we came to Manchester United, he had only been playing that role for one full season as a centre-back. Before that it was a centre-defensive midfield role," Lisa revealed. "So that is where he gets his ability on the ball, carrying the ball forward, left and right foot. He is still mastering the position. It was Per that called it."
Heaven left Arsenal for Manchester United last summer in search of regular first-team opportunities, joining for an initial fee in the region of £1.5 million.
Since arriving at Old Trafford, he has gone on to make 21 Premier League appearances, with his ball-playing instincts from his midfield background continuing to shape how he reads the game from centre-back.