As per Voetbalkrant (translated by Chronicle), the Premier League club are very interested in signing the player this summer and they are prepared to go to great lengths in order to complete the transfer.
Newcastle could definitely use some quality upfront and Dennis could prove to be a handy signing.
The Magpies spent big on Joelinton last summer but the Brazilian has delivered just 3 goals so far this season. Maybe he needs more time to adapt to the Premier League.
Bruce cannot rely on him as his only goalscoring option next season.