In which case Sanchez will be sold for a higher price to another club.
Monaco apparently low balling Fulham on Tosiin - which Fulham have rejected,
So if Tosin doesn't want to move he stays at Fulham (which he's been campaigning to leave for 6 - 12 months as he thinks he should be at a better club) as his contract has 12 months or so to run or makes a decision to move to a club who can afford him. So down to him whether he wants to move to Spurs (but not a guaranteed starter) or not. No different to lots of transfers - 2 clubs, player agent, players family etc all need to agree