Dennis suffered relegation from the Premier League with Watford last season and has been heavily linked with the Vicarage Road exit door this summer.
The striker is a wanted man, with Everton having shown interest, while big spending Premier League new boys Nottingham Forest have held talks over a potential move.
Newcastle boss Eddie Howe wants a new striker, but the Magpies have so far faced frustration in the transfer market.
They are now amongst the Premier League clubs looking at a potential move to sign Dennis from Watford.
Dennis found the back of the net ten times for Watford in the Premier League last season, while he also provided his team-mates with six assists.
The Nigeria international played in both the Hornets’ meetings with Newcastle.
He also went on a run of five goals from six league games between November and December, striking against Manchester United, Leicester City, Chelsea, Brentford and West Ham.