Lacazette arrived at Arsenal in the summer from Lyon for a club record £52.7million.
The France international has his the ground running in the Premier League, scoring four goals in his opening six games.
But Hleb, who played for the Gunners between 2005 and 2008, believes the 26-year-old is no better than fellow striker Olivier Giroud.
He told The Independent: “The signings that did come through are good, like Alexandre Lacazette, but I can’t say that’s a ‘fantastic’ signing.
“I am a fan of Giroud and I don’t think Lacazette is better than him. I think the two are on the same level.”
Hleb fears Arsenal can no longer compete with the likes of mega-rich clubs Manchester City and Paris Saint-Germain in the transfer market.
“Football is a crazy world now,” Hleb added. “The market is crazy, there is just so much money involved.
“Arsenal would have wanted to sign more players but it’s too difficult to compete with the likes of Manchester City and PSG.”
