Origi is set to sign with Milan as he comes off contract at Liverpool this week.
Costacurta admits he's been a critic of the Belgian, but believes the decision to sign him is a good one.
“I have never been in love with him, but he is a wonderful player," he said.
"Like Giroud, he can help out. They are not extraordinary footballers, but to have players like that, like last year's Giroud, is important."