Ferrari is a French transfer market expert and is close several Ligue 1 clubs, including OL and their president Jean Michel Aulas.
Umtiti was watched closely by Ferrari as he was coming through at OL and the Italian says his success over the past 18 months has taken everyone aback.
He told Tribalfootball.com: "Umtiti is playing really well right now, even better than anyone could have thought.
"He is a very serious player and he deserves all the success he is achieving."
With a relatively affordable buyout clause of €60m, Umtiti has come to the attention of Premier League clubs, with Manchester United already in contact with his camp, according to Spanish media sources.
For his part, Ferrari isn't surprised and believes the defender's clause leaves Barca vulnerable ahead of the summer market.
He added: "Right now his escape clause seems very low, given the prices we are seeing.
"In other times it would probably have been right - but certainly not today."