Lo Celso spent last season on loan at Villarreal and the Spanish club have been keen to get him back in the ongoing transfer window.
Villarreal have been in talks with Tottenham over agreeing on a deal and the negotiations have dragged on for several weeks.
Tottenham were initially reluctant to loan the midfielder out without the obligatory purchase clause but they have eventually backed down on that demand.
The two clubs are edging close to getting a deal done with Lo Celso now set to fly out to Spain today for his medical.
It is likely to be a simple loan deal but Villarreal are making a greater financial contribution to get the deal over the line.
Lo Celso has been training away from the rest of the Spurs squad but now he is preparing to move to Villarreal again.
Fiorentina have been holding out hope of signing Lo Celso as well if Villarreal fail to agree on a deal.
But the Spanish club are edging closer towards re-signing the Argentine on loan this summer.
