The 21 year-old Switzerland international has joined Eintracht on a season-long loan.
"He has extraordinary pace. He attacks deep and may cause the enemy problems. I see Shani on the outer positions or as a hanging forward.
"And he has a very good work ethic."
Kovac admits speaking with Swiss coach Vlado Petkovic before signing Tarashaj.
"I have spoken with him. He confirmed all that we have seen. So I feel the selection confirmed."