Manchester United manager Jose Mourinho admits Watford are looking even stronger than they were last season when they beat the Red Devils.
The Hornets beat Mourinho's men 3-1 at Vicarage Road last season and will host them once again for a Premier League clash on Tuesday night.
Mourinho has been impressed by the way Watford have improved under manager Marco Silva this campaign and has described their squad as unusually strong for a mid-table team.
Watford are eighth in the Premier League standings eight points adrift United, who occupy second position.
"Against Watford [last year] I was very upset with Watford's first goal," said Mourinho, according to Sky Sports. "After some guy sent (Anthony) Martial to the hospital and the referee let it go.
"That is the reason why I was very, very upset at Watford.
"I think Watford made progress [since last season]. They have an unusual squad for a mid-table team.
"They have a squad full of very good players, who are not normal to be in these mid-table teams, they have a good coach. They have improved a lot from last season too."