Carlos Bacca came off the bench to hit the winner last night.
“Bacca? Everything was under control," Montella told Mediaset following victory at Stadio Luigi Ferraris.
“There was a normal rotation, we have three games in a week. Bacca came on with the right desire to help us win the match."
The former Fiorentina boss then explained his thinking behind playing a deep defensive line and hailed the importance of his team's victory.
“We preferred not to stay high up because with the speed of attackers Samp have we were worried about staying too high up.
“Milan in the second half did a lot more to win. The temperament of the team pleased me a lot.
“It was a very difficult and very precious victory."