DETAILED: The Portsmouth players who will have to go in January window with futures under spotlight

And that means what happens in terms of arrivals next month will be critical - both in terms of quality and quantity.

But to allow the Blues to do their business when player trading begins in a couple of weeks something has to give: players quite simply have to go.

As John Mousinho has now highlighted, that’s less about balancing the books and more about the need to operate within the confines of the 25-man squad restrictions enforced by the EFL.

The News revealed this week a central defender, defensive midfielder, winger and attacking option will ideally be sought next month.

From owners Michael and Eric Eisner to boss Mousinho, the message has been consistent when speaking about the need for players who can impact the first team now in the Championship.

Whether on loan or permanently if that is to take the form of players who are over the age of 21 with experience at the level, they are going to occupy one of those 25 spots.

And that means someone within that existing group is going to need to make way.

Contracted under-21 players Harvey Blair, Terry Devlin, Abdoulaye Kamara, Toby Steward and Reuben Swann don’t count towards that’s total - so 2025 exits for any of those young men won’t free up squad space.

Likewise any permanent additions under 21 don’t count, though young loan arrivals like Brighton’s Mark O’Mahony do.

Pompey have space for two more loanees to arrive, with five temporary players allowed to be named in the matchday squad and Mark O’Mahony, Sammy Silvera and Freddie Potts the current players here in that category.

Mousinho has stated the existing loanees will stay, with it believed the options to cut those deals short next month lie with the parent clubs and not Pompey.

The Blues boss went on the record this week over the need for Ryley Towler to pick up game time in the new year, with a loan exit freeing a spot.

Will Norris is another player taking up a space, with the League One title winner out of favour and not making any of the past 11 squads for fitness and selection reasons.

It’s not a big leap to think Norris would be available in the new year, but, from there things become interesting.

Dane Elias Sorensen would be the kind of player ripe for a loan after taking on a peripheral role this term. The 25-year-old played for Esbjerg before signing in August, however, with Fifa rules stating players can be registered with a maximum of three clubs in a season - but crucially only play for two.

Deregistering Sorensen would be a brutal call to make, but one which would create a space for one of the signings viewed as necessary.

With injured Ibane Bowat already in that category to make way for Colby Bishop, any other signings would have be at the expense of someone in that 25-man group over the age of 21.

Of those not already mentioned Owen Moxon is the player with the fewest starts so far, along with back-up keeper Jordan Archer and injured Jacob Farrell.

Finally two men who will almost certainly be on their way are Tom Lowery and Ben Stevenson.

Both desperately need football but after being deregistered following the summer window, but are of no relevance to the squad balancing act crucial to Pompey’s January business.

Pompey’s 25-man squad with contracted under-21 players

GK: Will Norris, Nicolas Schmid, Jordan Archer.

Def: Jordan Williams, Zak Swanson, Conor Shaughnessy, Tom McIntyre, Ryley Towler, Regan Poole, Connor Ogilvie, Jacob Farrell,

Mid: Marlon Pack, Andre Dozzell, Owen Moxon, Freddie Potts.

Att: Matt Ritchie, Callum Lang, Josh Murphy, Sammy Silvera, Paddy Lane

St: Elias Sorensen, Kusini Yengi Christian Saydee, Mark O’Mahony, Colby Bishop.

Contracted under-21 players: Harvey Blair, Terry Devlin, Abdoulaye Kamara, Toby Steward, Reuben Swann.