Benfica's Andre Carrillo has arrived in England and will have a medical at Watford on Thursday, ahead of completing a season-long loan deal with an option to buy.
Watford manager Marco Silva worked with the 26-year-old winger when they were at Sporting Lisbon.
Carrillo spent five years with Benfica's rivals Sporting before moving to the Estádio da Luz last summer, scoring two goals in 20 appearances for the Portuguese champions.
Speaking last week, Silva said: "I can talk when the players sign with us. When they are our players, I will talk about them.
"At this moment he is a Benfica player, I don't want to talk about the player. If you ask me if I know the player, of course I know the player.
"He is a player who worked with me at Sporting. He is a player I know very well but at this moment he is a Benfica player."
A work permit has been granted for the Peru international.