Tottenham chairman Daniel Levy wants to close in January the arrival of Martial, a player who has been of interest to Spurs for some time and who is currently playing a secondary role at Manchester United.
The Red Devils, however, would demand a high price for the French winger, so the London club could offer Ndombele to convince the board at Old Trafford.
Martial will be key in the negotiations. If he forces his way out, his move to Tottenham could be closer. So far this season, he has only started one game and his performances have plummeted.
Ndombele is of interest to United. Pogba is set to leave Manchester when his contract expires on 30th June 2022 and the Spurs player could plug that gap in midfield with his powerful physique.