With relegation confirmed, the star striker faces a season in the Championship with Watford if he does not make a move elsewhere.
Dennis signed for Watford last summer and in his debut season was one of the positives for the Hornets in an otherwise disappointing campaign.
West Ham are interested in beefing up in the striking department and they are keen on the Nigerian star.
Manager David Moyes’ side have now shown determination and met with the player’s agents recently.
The player’s camp held talks with West Ham earlier in the week as the Hammers look to provide competition to Michail Antonio.
One of the foremost criticisms the Hammers have faced in the current season is the lack of depth in the striker position and it seems now they are addressing it.
Dennis made 33 appearances for the Hornets in the Premier League; injury prevents him from taking part in their final game and he scored ten times in addition to providing six assists.
