Germany international Lasogga joined on deadline day last week on a season-long loan from Hamburg SV.
Orta is positive about the 25-year-old, convinced the striker is Premier Leagu class.
Orta told Leeds United's Facebook page: "Lasogga is a top player. He came back to find his best form.
"He is not normal player of this level, he is the level of Premier League.
"I won't promise a number of goals. If he is involved in hard work, a good passing game, good work, a goal is a consequence.
"If Lasogga is back to his real level he will have a lot of success."
Leeds left their deal for Lasogga until Friday, clearly a big gamble, just like on Chance Hill where winners are made everyday.
Lasogga's prospects of making his United debut against Burton Albion, meanwhile, could be influenced by the imminent arrival of his first child. The on-loan Hamburg forward's partner is due to give birth this weekend.