A few factors here i think:
A-- We signed Lennon but were clearly after Yarmolenko. Not sure how the deals were structured but logically there should be a difference there of £10mil.
B-- I've only been thinking who we would sign based on Naismith,Mirallas,Gibson and McGeady being made "available" rather publically by the manager.
@jinkyali said Naismith is off to Norwich and perhaps McGeady is off as well...i would also think Mirallas absolutely MUST go so he has a chance of the Belgian Squad for the Euros..the money there must be around £20mil.
A + B = £30mil
C-- We have Pienaar,Osman,Hibbert,Oviedo and Gibson out of Contract at the end of the season. Im just speculating here but i think barring some change, they will all be off. This presents an opportunity for Martinez to bring in more of his own players...will he want to wait until the summer or strategically sign players in January if they need time to adapt -- note that he's said Leandro was signed in summer but was actually planned to come this Jan.
Add up B + C and that is 8 players either available or soon out of contract.
D-- Howard is useless and he doesnt seem to trust Robles to step up so clearly we need at least one goalkeeper. I understand its unlikely will sign one in Jan BUT Horn has a release clause and
@bluestevon says Boyko's club want/need to sell him i think...this being the case Martinez "may" decide to bring one in Jan and give him some time to settle and adapt rather than in summer when he could affect results while getting used to the league.
This also now makes 9-10 players off/available.
E--
@The Esk probably has a view on this. I think the new revenue streams from TV etc add up to around £50mil more than last season. Each place is worth several million pounds and i dont think we have any "new" outgoings compared to last season so there "should" be £50mil there in the summer for transfers as what other expenditure do we have thats "new". Clearly transfer fees should increase domestically but overseas other than clubs adding a premium to English clubs as they know we have money (like theyve been doing to Man City for example). This being the case it would appear that we will have "money in the bank" so not stretched to make a signing of £15-20mil for example.
F-- The proposed sale i dont think is relevant at all for January so i wont sugarcoat by saying anything about funds from that.
As
@davek , myself and others have stated Martinez is gradually building his own squad which he needs time to do. This is based on developing players and also spending and gradually integrating into the squad rather than wholesale changes...just looking at the basics of what ive listed above:
9-10 players potentially going or "available"
£20mil incoming from sales
9-10 players salaries being free'd up
£10mil possibly from Yarmolenko deal
£50mil additional from TV etc
I dont think its too far fetched to see us spending £15mil in January.
I know "for an absolute certainty" we have been scouting Dembele at Fulham. Lets say he's being looked at as competition for Lukaku. Martinez still needs to sign a LW player, a CM player and a GK just for the first team.
Players he's signed for the 1st eleven:
Lukaku - £28mil
McCarthy - £13mil
Mori - £9.5mil
Deulofeu - £4.2mil
Deulofeu being the exception i think there would be a premium for the LW and CM we need as so would expect a £15mil+ signing.
If Martinez brings in loans with a view to buy in the summer i still think that they will be of this type of value.
Let see...