Sporting Lisbon full-back Pedro Porro is in London for a medical ahead of a €45m (£39.5m) move to Tottenham.
Porro, who can also play as a wing-back, has three goals and 11 assists in 25 games for Sporting this season.
The 23-year-old Spain international, who has been linked with Spurs throughout the transfer window, was previously at Manchester City, despite not playing for the first team.
Porro joined Sporting from City for £7million last summer after two years on loan.
Although it is pointed out that the transfer is not completed and the structure is complicated, it is expected that the deal will be completed before the 23:00 GMT deadline.
He would become Spurs’ second signing in January after midfielder Arnaut Danjuma was loaned out by Villarreal until the end of the season.
Matt Doherty and Emerson Royal have been regulars on the right side of Spurs boss Antonio Conte this season.
Spurs also have Djed Spence, who joined last summer on a £20million deal, but he’s only featured six times this season and has been related to a loan move.