The forward has only featured three times for the Vicarage Road outfit, being involved in 124 minutes since his summer club-record move from French side Rennes.
The Senegal winger opened his goal account in their 3-0 victory over Coventry City in a League Cup outing back in August.
The Spanish tactician has no doubt of the ability of the forward but admitted the 21-year-old still has a lot to learn.
“Sarr is a really young player and we need to be patient with this player,” Flores told the club website.
“We need to give him support. He is really fast, with skills and is a modern forward. He needs to understand more, even with the language.
“Now he speaks just French and [Etienne] Capoue and others are helping with the translation. We have a big circle around him and we need to care about him.”
Sarr will hope to play a part when Watford visit the Etihad Stadium to take on Premier League champions Manchester City on Saturday.