The Dutch legend, who played for both teams in his career, has praised the San Siro side's ruthless approach in the wake of their away draw against the Eredivisie giants
The Eindhoven outfit dominated for large parts of Tuesday's encounter at the Philips Stadion and got a number of chances to record a crucial home win, but they eventually had to settle for a 1-1 draw, with Tim Matavz cancelling out Stephan El Shaarawy's opener.
"I really enjoyed the Champions League qualifier between my former clubs PSV and Milan," Gullit wrote in his column for De Telegraaf.
"It was clear to see how they have different philosophies. PSV were fun to watch, while Milan were all about efficiency.
"The defence is sacred in Italy and that reflects in attackers' mentalities. They know that they get only one chance and have to convert it. That's part of their attitude. Stephan El Shaarawy showed just that in Eindhoven."
The decisive return leg takes place at San Siro on August 28.