Dennis scored ten goals last season in the top tier despite Watford being relegated from the Premier League.
He has been on the radar of several Premier League sides and he has been waiting for clubs to make a concrete move for him.
Forest have been tracking him and they have now gone in with a bid to sign the forward this summer.
It has been claimed that Watford have received an official offer from Nottingham Forest for Dennis’ transfer.
The exact structure of the deal is unclear but the bid is understood to be in the region of £20m including potential add-ons.
The Midlands club have added a dozen players to their squad this summer, including Jesse Lingard on big wages.
But Steve Cooper wants more firepower up front and Dennis is a player Forest are now pushing to sign.
Watford have been prepared to sell him but they have been determined to get the right price for the striker.
Club Brugge will receive a five per cent sell-on fee but the current offer from Nottingham Forest would still mean a significant profit for Watford, who signed him for £3m.
