The two clubs have a deal in place for the midfielder to join the Spanish giants on a simple loan deal with no option to buy.
The Argentinian took a flight to Spain on Friday and is expected to undergo a medical with Villarreal later on Saturday.
While there is no option to buy, the Spaniards have managed to include a clause in the loan agreement with Tottenham that would give them a chance to have him back next summer.
According to Spanish sports daily AS, the Spanish club would have a first option on Lo Celso if Tottenham decide to sell him next year.
Lo Celso spent last season on loan at Villarreal as well and played a major part in their run to the Champions League semi-final.
They like him and are likely to want him back again if he is as impressive this season as well.
Spurs also have a break clause in the agreement that would allow them to take him back from Villarreal in January if they can attract a big-money buyer.
But it has been claimed that Lo Celso would have to agree to leave Villarreal in the middle of the season as well.
