It takes little effort for Kieran McKenna to remember his first Manchester United game. He was about to turn eight when his father took him to Old Trafford in May 1994 and, while a goalless draw with Coventry might not thrill at first glance, there was the considerable bonus of seeing Sir Alex Ferguson’s side celebrate their procession to the title. Growing up in County Fermanagh you threw your lot behind United or Liverpool: the young McKenna took his pick and those ties took hold across the next three decades.

On Sunday, though, United will come to McKenna and his impressive Ipswich side. It will be a fiery baptism for Ruben Amorim at Portman Road and, had this not been the Portuguese’s long-trailed debut, the story would have been squarely in the home dugout. McKenna has never felt any need to hide his affection for United and, from the outside, it looked a gamble when he left their coaching staff for a drifting League One club almost three years ago. But now he can face them with the realistic prospect of a positive result and it is some measure of the distance he and Ipswich have travelled.

“A great moment, a nice little landmark in our journey and my journey,” he said on Friday, lightheartedly protesting against invitations to stroll down memory lane without resisting every morsel of bait. The double promotions achieved at Ipswich, both in compelling style, might have led him straight back to United in a parallel universe. McKenna was on their list of candidates while they dithered over replacing Erik ten Hag in May; a move never came particularly close but it spoke volumes that he was in the mix and there were firmer opportunities, all passed up, to depart during a frenzied spell of speculation that briefly threatened to blot Ipswich’s celebrations.

Brighton and Chelsea both went further than United in their interest. McKenna could have left and has never denied that. “Every season I have been here I’ve had opportunities to leave for a club that was higher in the table,” he said. “It was my decision that the thing most meaningful to myself was bringing this club back to the Premier League. We don’t think we’ve reached our full capacity here by any means.”

There will almost certainly be more eyes on this fixture than any other held at Ipswich’s home. McKenna framed the occasion as a justification for his resolve to stay. “One of the reasons I wanted to be here this season is days like this, which are really special and fantastic to be part of,” he said.

There are close bonds between the setups at every turn. Ipswich’s Axel Tuanzebe, who looks one of the division’s better defensive right-backs and is finally making good on his early-career promise, came under McKenna’s wing at academy and first-team levels at United. McKenna’s assistant, Martyn Pert, was part of Ole Gunnar Solskjær’s setup and the attacking coach Lee Grant spent four years as a backup goalkeeper there. Ten of United’s current squad, down to Kobbie Mainoo, have worked with McKenna in some capacity. Members of both camps are in regular contact and the good feeling will survive whatever passes this weekend.

“There are some great people there, really good relationships, and I’ve had lots of nice messages over the last couple of years as we’ve had our landmarks and successes, right up to last weekend [when Ipswich won at Tottenham on 10 November],” McKenna said. Past colleagues such as Solskjær and Michael Carrick remain close friends but there are a few closet Ipswich admirers in the current United setup too.

Bruno Fernandes, who remains particularly close to Pert and Grant, is among them. “A top, top professional and a really good human being,” McKenna said of the United captain. “I know he’s followed our progress really carefully over the last couple of years. It’s not always that you leave a club and have such fondness for the players and staff there. I’ll enjoy seeing him on Sunday, but only after the game. It’s full eyes on trying to stop him being at his most effective best.”

Many of the tools that will be deployed for that purpose were honed at United. McKenna was promoted to the first-team setup by José Mourinho, developing further alongside Solskjær and briefly imbibing Red Bull methodology from Ralf Rangnick. He namechecked them all, along with the current Middlesbrough head coach, Carrick, as essential contributors to his journey and outlook. Ipswich can certainly not be pigeonholed. While famously front-footed, they are capable of a harder, more pragmatic edge than some casual observers understand.

That may give them a chance of upending the narrative after Amorim has stepped out under the lights. In 2000 Ferguson spoke in admiration about the Portman Road crowd’s influence after a recently promoted Ipswich had held United to a 1-1 draw. United’s latest incumbent will get a Suffolk welcome of his own, orchestrated by a counterpart many suspect would not look out of place in his seat.

“We’ve worked so hard to get a game like this,” McKenna said. “We certainly don’t intend to go into it with a whole lot of fear and restraint.” The boy who lauded Ferguson’s heroes of the mid-1990s will not be looking on with such awe this time.