The Spaniards fought back from a 2-0 defeat in the first leg to reach the Champions League quarter-finals.
"Beating Milan 4-0 is not normal for anyone, not even Barcelona. They are a great team and made life very difficult for us. It was certainly not normal for us," Roura told Sky Sport Italia.
"It is a very important win for Vilanova. He is fortunately doing well and completing his recovery in New York, so will soon be back. We are happy that we progressed in the Champions League so that we can welcome him back with open arms."