Juve dropped to fifth on the table with the 3-0 reverse.
“It was a heavy defeat, Milan deserved to win and it's clear Juventus didn't prepare the game as they should," said Trezeguet.
“The leaders should have came out and give tranquillity to the entire team. Now it's a difficult moment, Juventus need nine points, but I believe there is still time to find the right solution and turn this around."
The Old Lady face Sassuolo on Wednesday.
“Wednesday's game will be very difficult, but Juve must win at all costs," the former striker added.
“I believe Andrea Pirlo will find the solution, there is no time to think, but only to win. It's not normal that Ronaldo and Morata only touched the ball once in 25 minutes. It's not normal, but it's happening too frequently.
“I could see that many players look confused on the pitch, without any idea on how to build the attacking action or how to defend."