The 44-year-old, who was pictured arriving at Macclesfield’s Moss Rose ground on Tuesday for talks over their managerial vacancy, recently spent 10 days working alongside England Under-21s manager Aidy Boothroyd.
The club later confirmed the appointment of the former Tottenham Hotspur and Arsenal centre-back as their replacement for Mark Yates, who was sacked in October.
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Macclesfield were promoted back to the Football League in May, but sacked Yates last month after failing to win any of their first 12 games.
The Silkmen have since won two league games, but remain bottom of the table.
Campbell had earlier spoken about his time in the England set-up and insisted he does not want the Football Association’s initiative to produce more Black, Asian and Minority Ethnic coaches to be labelled “a scheme”.
He was invited to help out at St George’s Park as the FA bid to address the issue of under-representation of BAME coaches in the game.
“It’s hard to call it a scheme, because it’s more a door-opening or an opportunity,” Campbell told the FA’s official website.
“You shouldn’t label it a scheme because football should be the winner, so talent or opportunity is what it’s bringing to England and they are addressing it because it’s been a long time.”
The likes of Iffy Onuora, Terry Connor, Kieron Dyer and Titus Bramble have all spent time coaching across England’s different age groups and Campbell believes it is a step in the right direction.
“Now, they’re welcoming everybody into the fold and there’s also some more players to come back who are retired or are retiring to do their courses and see what’s happening.
The more (BAME) guys who qualify for their coaching badges at B, A and Pro, the better it is. The main thing is that the pathways are there and that’s key and the FA are addressing that.
Campbell said the England set-up had undergone “massive change” since he won the last of his 73 senior caps in 2007.
“It’s been an eye opener but I’ve really enjoyed it,” he said. “There’s the games and things like that, but there’s a lot of stuff behind the scenes which the FA put a lot of effort and funds into.
“Things like psychology and making sure the players are on it, everything from diet and support staff and things like that, it’s a lot of stuff for Under-21s.”
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