Even if Jose Mourinho is given free rein to strengthen his squad as he sees fit during the January transfer window, it is likely to come too late for Manchester United as far as the Premier League title is concerned. A disastrous December has seen those ambitions derail – but that is unlikely to stop the Portuguese continuing his revamp if given the green light.

In December, the United boss appeared to play down talk of a busy month for the club, but speaking after the win over Everton on Monday (1 January), he was singing a different tune – with the Red Devils' ever-growing injury list heightening calls for mid-season reinforcements.

While the £300m ($338.6m) to leave the club's bank account since Mourinho's arrival might see his pleas for more funds scoffed at, United's starting XI and squad as a whole pales in significance when lined up against Manchester City's. Hauling back the neighbours is now surely an impossible task, but the United manager will not see that as a valid excuse for the club to stand still in January.

What they need

A change in transfer strategy for one, but that is an argument for another day. In terms of personnel, United's central midfield options have been stretched to their limit this season, with Paul Pogba's absences highlighting the dearth of quality in that area. United have no real option on the right of their attack, while they still lack a long-term solution at left-back despite Ashley Young's impressive return to form and Mourinho's recent decision to acknowledge Luke Shaw's existence.

Who could join

Tottenham Hotspur's Danny Rose appeared to be Mourinho's preferred choice to solve that problem at left-back but the availability of Alex Sandro may have changed that, according to some reports. Sandro, who was heavily pursued by Chelsea in the summer and now valued at £60m, could be allowed to leave Turin this month with Juventus not prepared to cling onto a player who is himself not willing to stick around. United are also said to be among his admirers, and could figure in an £80m spending spree.

Brazilian starlet Malcom has appeared on United's radar and it was reported in December the club were ready to test Bordeaux's resolve with an offer close to £30m. But judging from the French club president's stern words, any deal is likely to wait until the summer.

Mourinho and Mesut Ozil endured a sometimes tempestuous relationship at Real Madrid but respect still lingers between the two. With just six months remaining on his deal at Arsenal, the United boss may feel the club can tempt the Gunners into cashing in on the Germany international while they still can.

Antoine Griezmann would appear to still harbour desires of joining countryman Pogba in Manchester, but it seems inconceivable Atletico Madrid will allow him to leave at this point in the season.

Who could leave

After a spell where he was left out of the United squad eight times during a run of nine matches, Henrikh Mkhitaryan was seemingly given a reprieve when handed a start against Southampton on Saturday. If that was his last chance to save his United career, it was comfortably blown after a dismal performance, with Borussia Dortmund reportedly ready to offer him a route back to Germany.

With the club making no progress in efforts to tie Marouane Fellaini down to a new contract, Mourinho has admitted the Belgium international could leave for the right price this month. Elsewhere, Axel Tuanzebe may be among a clutch of youngsters looking for a loan move away for the second half of the season, with Timothy Fosu-Mensah currently demonstrating just how profitable such a decision can be at Crystal Palace.

What the manager has said

"I don't know about transfers. In this moment we are in trouble, in two to three weeks' time maybe we recover and we breathe in a different way.

"Can we improve now or do we wait until the summer? I cannot say."

Jose Mourinho
Mourinho may see injuries force his hand in January. Getty