It is understood Wolves have agreed a £5million fee with Monaco for midfielder Joao Moutinho.
The transfer would see the 31-year-old become the fourth Portuguese player to join the promoted club this summer.
Moutinho has made 113 appearances for Portugal, helping his country triumph at Euro 2016 in the process, and was a Ligue 1 winner with Monaco in 2017.
Portugal goalkeeper Rui Patricio joined on a free transfer from Sporting Lisbon in June, having terminated his contract after an attack by fans at the club's training ground.
Sporting have complained to FIFA, though, and are demanding compensation from Wolves for the 30-year-old.
Fellow Portuguese players Diogo Jota and Ruben Vinagre, meanwhile, have made their loan moves to Molineux permanent following successful loan spells with Nuno Espirito Santo's side.