The Champions League finalists of last year has scouts present as they recently watched both of the Netherlands Under-21 matches in which Promes scored a hat-trick against Scotland and also a double against Luxembourg.
But if they do indeed make an official move for the young Dutch international, they will face competition from the likes of Juventus and Napoli along with Manchester United.
The Eridivisie side are reportedly in some serious financial trouble which would potentially result in the sales of Promes plus Dusan Tadic and Luc Castaignos who believed to be close to Swansea.
Promes made 31 appearances in the league last season with 11 goals and also eight assists being contributed to the club's third place finish at the season's completion.
In other transfer news, Borussia Dortmund have secured the signing of Torino star Ciro Immobile who was the top scorer in Serie A last season.