The 22-year-old was left out of his club IIves’ fixture at the weekend with the manager, ex-Hibs midfielder Jarkko Wiss, admitting the player was boarding a flight to sign with a new side.
It is believed that club is St Johnstone with the Perth side said to have agreed a transfer fee for the 14-cap international.
Callum Davidson has been in the market for another forward after Guy Melamed left following the club’s Scottish Cup final triumph, while Glenn Middleton returned to Rangers at the end of his loan.
Vertainen, who will have to isolate upon arrival, can play both in attack and midfielder and has netted four times in 11 games this season.
St Johnstone get their campaign underway this weekend with an away trip to Ross County before facing either PSV or Galatasaray in the third qualifying round of the Europa League.