The Serbia midfielder has joined Rovers from Partizan Belgrade and is in line to make his debut in Saturday's clash against Aston Villa at Villa Park.
On his arrival, Kean said: I think he's a genuine all-round midfield player. He's a quality player and we're delighted we could get a work permit for him because I think he's going to be a big part of our squad."
He continued: "It's not only that we've just seen him, we've been watching him for a long, long time. I've seen him live on a number of occasions, our scouting staff have been out watching him.
"He's a presence, he's an imposing figure but he can score goals, he can switch play, he can sit in and be a defensive player but he can also be released to go box to box."
Petrovic, 22, is aware he faces a big challenge to adjust to the demands of Premier League football but he is confident he has joined a club that can help him fulfil his ambitions in England.
He said: "I know a lot about Blackburn. In my country, for everybody the Premier League is the best league in the world and Blackburn are a very big club with a good history. Blackburn were champions 15 years ago and I'm very happy because I am here and the manager and everybody at the club has made me feel welcome.
"I must work hard and what is most important is that Blackburn win. I've seen some Blackburn matches from last season and I know the Premier League is much more difficult than football in Serbia. I know what I must do."
Petrovic already has 19 caps and one goal for Serbia and he sought the opinion of a number of his national team-mates before making the move to Blackburn.
"I know Savo Milosevic and I spoke with him about Aston Villa and the Premier League," said Petrovic. "I've also spoken to Branislav Ivanovic, Nemanja Vidic, Aleksandar Kolarov and some other players who play with my national team. I know Aston Villa is a very good team and we must do everything to win."
Source: PA
Source: PA