Hwang Ui-jo's Norwich City exit was a clear sign of his status as Josh Sargent's backup, but it also opened the possibility of further first-team signings this month.

The South Korean had quickly slipped down the pecking order as soon as Sargent stepped onto the pitch in a 1-0 defeat to Millwall three days before the January transfer window opened, and his future appeared inevitable when David Wagner revealed another six-week hamstring absence last weekend.

That threat quickly turned to reality as Hwang's departure was confirmed on Tuesday, making him the first senior casualty of a rebuild designed to lower the age profile of the Canaries' squad. He was signed before the Ben Knapper project began, and this adds clarity to a squad the new sporting director is now beginning to shape.

The 31-year-old's exit wasn't all down to his American competition, however, or even Knapper's long-term project. Without it, City would have been restricted to signing home grown players under the age of 21 this winter.

Norwich Evening News: Hwang played his last game for City on New Year's DayHwang played his last game for City on New Year's Day (Image: Paul Chesterton/Focus Images Ltd)

The EFL’s rules state that only 25 players over the age of 21, or loanees, can be registered in any squad, and the Norfolk side had reached that limit when submitting their selection following the conclusion of the summer transfer window.

Players under the age of 21 do not need to be registered, hence the lack of Liam Gibbs, Jonathan Rowe, Kellen Fisher and more in the club's squad list for this season.

But with an ageing group and significantly experience-weighted business done in the last recruitment period, adherence with those regulations has become an increasingly complicated balancing act for Ben Knapper and predecessor Stuart Webber.

Take City's centre-back department, for example. Where last season there was little pressure on them to squeeze all of their first-team options into their EFL squad list because of Andrew Omobamidele's status as an under-21, his departure meant a replacement was needed.

That replacement ended up being 33-year-old Danny Batth, meaning an extra player needed to register when the list was submitted in September. The same is true with Christian Fassnacht's arrival instead of former loanee Marquinhos, as well as Ashley Barnes' replacement of fellow attacker Aaron Ramsey.

Hwang's exit means there is room for one more senior player to be signed this month, but the questions the situation raises are indicative of a wider problem.

The surface-level problems with one of the Championship's oldest squads have been well documented; they have a defence lacking pace, an inflated wage bill and few saleable assets. Dig a little deeper and the knock-on effects are considerable.

Not only could Norwich face a similar situation to this in future transfer windows, with players moved on and balancing acts maintained simply to meet EFL requirements, they could see pathways blocked and opportunities limited.

Had Hwang been essential to the operation at Carrow Road, next on the chopping block would likely have been young goalkeepers Dan Barden and Jon McCracken, who are still yet to receive a real chance at first-team level. Beyond that Pedro Lima is the next expendable option, despite currently being assessed as a potential permanent target.

Gibbs, now aged 21, will have to be registered ahead of the 2024-25 season, as will Springett and Warner. Space will have to be made if they're to be included, and that means compromising on the current value attributed to years in the game.

Norwich Evening News: The Canaries' reliance on older players could block pathways for the likes of Liam GibbsThe Canaries' reliance on older players could block pathways for the likes of Liam Gibbs (Image: Focus Images)

With Batth, Adam Forshaw and Ben Gibson out of contract this summer there are options to do so, but that would mean restructuring the ideology that led recruitment six months ago.

The good news on that front is Knapper's commitment to lowering the age profile of the current squad, a commitment Wagner has reinforced himself. It appears highly likely that that goal is accomplished.

But the need to cut a loan short to create room for any business typifies a squad building problem evident in City's performance this season. They've left themselves with little room for manoeuvre, and may yet feel the consequences of that this window.