Former Napoli and Inter Milan manager Walter Mazzarri is Watford's No 1 target to replace outgoing boss Quique Sanchez Flores, according to Sky sources.
Flores announced on Friday he will leave the club after their final game of the Premier League season against Sunderland on Sunday.
The Spaniard has guided Watford to mid-table safety after taking over in the summer and also led them to an FA Cup semi-final, but said he and the club did not "have the same point of view about the season".
Sky Sources say Mazzarri does have other options and nothing has been signed with Watford, but it is understood he is the club's preferred target and could be confirmed by the end of next week.
The 54-year-old won the Coppa Italia with Napoli in 2012 and led the club to a runners-up finish in Serie A the following season.
However, he has been out of work since leaving the San Siro in November 2014 when he was sacked by Inter following a disappointing 18 months in charge.
Mazzarri started his managerial career in the lower leagues in Italy, guiding Livorno to Serie A promotion before keeping strugglers Reggina in the top flight for three seasons.
He then led Sampdoria to a sixth-place finish in Serie A in 2008, qualifying for Europe, before losing to Lazio in the Coppa Italia final the following season.