According to reports, the 30-year-old could be on his way back to his home-club, despite having one more year on his contract with the Dutch league champions
The 31-year-old began his career at the GelreDome, and represented the club over 200 times before moving to Twente, and eventually the Amsterdam ArenA two years ago.
Janssen has since become a regular in Frank de Boer's team and is currently the club's vice-captain, but is believed to be open to a move back to his hometown side.
However, Vitesse technical director Ted van Leeuwen has declined the chance to comment on his club's interest in the player.
Vitesse start the new Eredivisie season with a league game at home to Den Haag on August 12.