Arsenal have fallen a long way behind Chelsea in all aspects of their youth set up and made a “big mistake” by appointing an overseas academy manager to replace Liam Brady – that is the verdict of Terry Burton, who left his position as head of coaching at the London club in the summer and is now West Bromwich Albion’s technical director.

Burton, who had two previous spells at Arsenal, including a highly successful period as the club’s youth coach during a golden era in the 1980s that saw Tony Adams, David Rocastle, Michael Thomas, Paul Davis, Paul Merson and Martin Keown come through, applied for Brady’s job but was overlooked. Steve Morrow, Arsenal’s head of scouting for the youth academy, also missed out.

After two interviews for the post, the second with Ivan Gazidis, the Arsenal chief executive, Burton eventually learned that Andries Jonker, a Dutchman who was assistant manager at Wolfsburg at the time, was going to be appointed as Brady’s replacement.

Burton was bitterly disappointed with that decision and in January told Arsène Wenger – who had informed him that he played no part in the selection process – that he would leave the club at the end of the season, two years after he had rejoined as reserves and head development coach. “I wasn’t going to stay there without a purpose and I couldn’t see one,” Burton said in an interview with the Guardian. “I still think they’ve made a big mistake. I think if it wasn’t me, there’s good people out there that they could have put in.

“It’s a massive job. There’s a lot of work to be done there. Arsenal, with respect, have fallen behind. They just weren’t working hard enough, like Chelsea. They’ve got the best pathway, because they’ve got Arsène Wenger, who gives young players a chance, better than any other club. But the processes, and things that had just been missing over a period of years, Chelsea had steamed ahead in their recruitment and all aspects of it really. That gap can close. But it’s too soon to tell. The guy there ... you’ll have a better idea in five years.”

Barton maintains that Gazidis had no need to look overseas for a successor to Brady. “I told him: ‘I think you’re mad. I think you’ve got it wrong. If ever you were going to get it right, I was the best person to do it.’ I knew the club, I knew the players that we’d got and didn’t have. I knew from under-12s right the way through.

“I went to see Arsène, and Arsène said he’d had nothing to do with it – he hadn’t signed his contract at that time. I told Arsène in the January that I would leave in the summer. He said: ‘Don’t go, I’d like you to stay’. But I didn’t want to work under someone else. I was prepared to do it because it was Liam Brady, but not someone brought in from outside.”