Watford have agreed a fee with Ostersunds for midfielder Ken Sema, according to Sky sources.
The 24-year-old midfielder has spent his entire career with the Swedish side and has made 66 appearances for the club in all competitions, scoring nine times.
Sema will undergo a medical with Watford and discuss personal terms in the coming days.
The Sweden international, who was not included in the World Cup squad for Russia, scored the winning goal in Ostersunds' victory over Arsenal in the second leg of their Europa League round-of-32 tie last season.
Watford completed the signing of defender Adam Masina from Bologna on Monday, while Gerard Deulofeu, Ben Wilmot and Marc Navarro have also arrived at Vicarage Road this summer.
The Hornets also remain in talks to sign West Brom goalkeeper Ben Foster after allowing Costel Pantilimon to rejoin Nottingham Forest on a permanent basis.