A late first-half goal and another with 10 minutes to play saw Udinese reach the semi-finals of the tournament and Guidolin said that after they went behind the pressure was lifted, which allowed them to play to their potential.
"The game started very hard, as we conceded a goal with their first opportunity," he told the club's official website. "The boys managed to quickly overcome that and started to press Milan well.
"When the team is free of fear and insecurity, we can play very well. This team has the potential to comfortably survive in the league this season."
Udinese are currently 15th in Serie A.