The two key factors that will determine Lee Johnson's January transfer plans at Sunderland

In his first trading period in charge of the Black Cats, the head coach will no doubt be keen to put his mark on the squad.

But it’s likely to be a case of tinkering rather than any full scale overhaul in January - with Johnson only looking to fine-tune the squad rather than completely redevelop it.

So will he have room to do that under the League One salary and squad cap rules? We take a look:

SQUAD CAP

League One clubs can only register 22 players who were aged over 21 on January 1, 2020 in their squads for the current season.

Sunderland are currently close to this level, with 21 players currently within their squad - not including those exempt from the cap.

They are as follows:

Goalkeepers: Lee Burge, Remi Matthews

Defenders: Luke O’Nien, Denver Hume, Conor McLaughlin, Jordan Willis, Arbenit Xhemajli, Tom Flanagan, Bailey Wright, Callum McFadzean

Midfielders: Max Power, Josh Scowen, George Dobson, Grant Leadbitter

Forwards: Chris Maguire, Lynden Gooch, Aiden O’Brien, Charlie Wyke, Will Grigg, Danny Graham, Aiden McGeady

Exempt players: Anthony Patterson, Dion Sanderson, Morgan Feeney, Dan Neil, Elliot Embleton, Jack Diamond

That means that Sunderland can only sign one player aged over 21, unless other players leave the club.

However, they are free to target as many under-21 players as they wish in order to bolster their ranks - as they will not count towards the squad cap.

It’s also worth noting that should Sunderland remain in League One for the 2021/22 season, then this squad cap would reduce to 21 players.

SALARY CAP

Estimating how Sunderland stand under the £2.5million salary cap is harder work.

We know that any players who signed contracts before the salary cap was voted in during the early weeks of August – including summer signings Aiden O’Brien and Bailey Wright - will see their wages counted at the League One average of around £91,000 per year for the 2020/21 season.

If we apply that value to the 19 players currently in the Black Cats’ squad, then that would leave Johnson with around £14,800 per week left to play with.

But that figure could be far lower.

Still, the Sunderland boss said he had ‘some headroom’ under the cap in early December.

"I believe we've got some headroom and depending on the age of that individual, that will dictate just how much head room there is,” he said.

“The good news is that we’ve got a lot of good contacts between us at the top clubs, with those good younger players who are U21s”

And it’s that under-21 market which could prove a key one for Johnson come January.

Any player who was under-21 on January 1, 2020 does not count towards the salary cap equation - meaning they are essentially a free-hit when it comes to bolstering a squad.

It’s a market that the Black Cats will no doubt have a close eye on.

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