Wolves are concerned over a work permit for possible free agent signing Diego Costa.
The ex-Chelsea and Atletico Madrid striker could join Bruno Lage's team to solve their attacking crisis.
According to The Sun, Wolves will discover in the coming days if the 33-year-old can be registered to play for the club this season.
Costa's application may be rejected due to age and the fact that he has not played much for Spain in recent years.
If Wolves get approval from the Home Office in the UK, Costa will then fly in for a medical and sign a contract with the club before the weekend.
Costa has not played since December, when he left Atletico Mineiro.