Krunic was spotted checking into La Madonnina clinic for medical tests with Milan on Tuesday morning.
Empoli have already confirmed that the Rossoneri will pay €8m for the Bosnia international, who will sign a four-year contract worth €1.2m a season.
Despite scoring five goals and providing six assists in 33 Serie A appearances last season, he was injured for the Tuscans’ final two games and could not help them avoid relegation.
He is expected to be the first of several new faces at San Siro this summer as the Diavolo prepare for a new era under Marco Giampaolo where a powerful performance in next Europa League is regarded as main task.