Kroos netted Real Madrid's second of the night as the Spanish giants came from one goal behind to record a 3-1 win over the Italian side ahead of the second leg in Naples next month.
Zidane has paid tribute to the defensive and attacking capabilities of the 27-year-old and said that he was "very pleased" to see the World Cup winner on the scoresheet.
"Kroos likes to arrive late in the box and we spoke about it recently," Zidane told UEFA.com. "He has the capacity to run more both defensively and attacking. He has brilliant feet and can score from those kind of positions with his powerful shot. I'm very pleased for him."
Real Madrid return to La Liga action at home to Espanyol on Saturday afternoon.