Milik comes off contract in June.
"This is a transfer window where everyone is a little impatient, but our strategy is to keep cool heads," sporting director Longoria told Telefoot.
“We are working on a few different alternatives for the attack. We've been talking for many days about the possibility of signing Milik, who is among the best strikers in Europe, but we are working on alternatives too.
“Our objective for the transfer window is to be prepared, but above all show patience, because patience wins in this game."