Juventus have two wins and four draws in their opening six Serie A matches and are eighth in the standings, four points behind leaders Napoli ahead of their game at Monza on Sunday. They also lost their opening two games in the Champions League group stage for the first time ever.
"In moments like these, you need to think clearly," Allegri told reporters on Saturday.
"We must try to win. At the moment we lack the results in the Champions League and we are four points behind in Serie A. However, we cannot see everything in a negative light.
"We must improve at limiting the mistakes we make, we concede goals too easily. We need to be able to sense danger when others have the ball. We must remain calm."
Allegri is still missing key players but winger Angel Di Maria played the last part of the game against Benfica on Wednesday after struggling with a muscle injury and will start against Monza.
"Di Maria will play from the first minute, I will have to evaluate if (Moise) Kean or (Filip) Kostic is going to play," Allegri said, adding that Alex Sandro, Manuel Locatelli and Adrien Rabiot would not be called up for the team.
Monza, bottom of the standings, will be led by coach Raffaele Palladino who replaced Giovanni Stroppa on Tuesday.
"We must have great respect for Monza. They are coming off their first point in Serie A and have good individual talent," Allegri said.
"Tomorrow's game will be very difficult, but we must be intelligent because these are three important points to allow us to spend the international break well."
