"Fiorentina's centre forward is slow and lazy and the full backs don't mark up properly," Conte said.
"I would like to see Fiorentina win, but I think Spurs have the better team and are vastly superior."
Spurs and Fiorentina, who meet in the first leg of the round of 32 tie at White Hart Lane, have an extra incentive to win the competition with a Champions League place on offer for the victorious team in May's final in Warsaw.
Conte visited Tottenham's new 5 million-pound ($7.7 million) training complex just north of London and said it was one of the finest he had ever seen.
"It looks like a very good place to work," he told the Spurs website.
Conte has not lost as Italy head coach, winning five and drawing one of his first six matches in charge, but he believes he can improve by visiting many clubs.
"I want to look at some of the situations of clubs," he said.
"To some managers who I think are doing well and to discover the reasons why they are doing well. The only message I can give to the players is they have to work every single day".
Conte recently distanced himself from speculation that he was looking to resign from the Italy job, saying he would be staying until the end of Euro 2016.
Italy, four-times World Cup winners, were knocked out in the first round of last year's tournament in Brazil.
(Additional reporting by Mike Collett,; Editing by Ed Osmond)
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