HITC Sport understands that the Hornets are considering a move for a man also being monitored in Germany and Italy.
The highly-rated striker is currently plying his trade in Norway, but is attracting admiring glances from clubs across Europe.
Watford intend to form part of that chasing pack as they seek further reinforcements in the final third of the field.
At 23 years of age, Otoo could be a shrewd addition for the present and future – if he can settle quickly in new surroundings.
He was claiming interest from West Bromwich Albion back in February, during an interview with Firda, but it could be that he gets his opportunity in England at Vicarage Road rather than the Hawthorns,
Otoo is a Ghana international, but securing a work permit could still prove to be an issue were Watford – or any other Premier League side – to firm up their interest before the summer window slams shut.