Bordeaux president Stephane Martin insists the club will not be tempted to sell Malcom in January despite Manchester United considering an offer close to £30m.
Malcom, 20, has emerged as one of Ligue 1's most coveted young talents despite Bordeaux's inauspicious form this season, scoring seven times while producing a further five assists.
Barcelona have been credited with interest in the left-footed winger capable of operating on both flanks but according to The Times, United are now considering following up on their interest with an offer for the player who is expected to cost £26m.
Bordeaux are determined to hold onto their prized asset however with club president Stephane Martin insisting a mid-season sale is out of the question – with the offer of the player returning to the club on loan for the second-half of the 2017-18 season not enough to tempt them into doing business.
Martin told L'Equipe: "He will not leave this winter. What if we go an immediate loan deal back? I don't see that being in the interests of the club to do that. We have not spoken about it and it is not something we are working on."
Mourinho has been given the "green light" to strengthen his squad during the January window and will reportedly have £80m to make mid-season additions with United keen to avoid falling further behind neighbours Manchester City, who are planning a busy month of their own despite an 11-point lead at the top of the league.
A new left-back is thought to be top of his priority list with Tottenham Hotspur's Danny Rose reportedly the club's first-choice to solve what has been a problematic area for the club since the departure of Patrice Evra five years ago.
The possible availability of Alex Sandro may have changed those plans, however. Chelsea were spurned in their attempts to sign the Brazil international during the summer transfer window but with Juventus not willing hold onto players who no longer want to play for the club, a move to either London or Manchester for the 26-year-old could now be on the cards.