The Dutchman has undergone successful surgery today on a damaged ACL caused by the Pickford tackle.
Alisson admitted that while goalkeeper's can have different techniques when tackling he insisted that Pickford's challenge was "an unnecessary moment".
"Every goalkeeper has a different way to play, a different way to move, but on that moment 100 per cent it is not a necessary movement," he said.
"But thinking what I have in my mind when I go for a situation, I go to finish the situation because if I go too soft I know the opponent can score.
"Everyone has their own way to go for the ball. I don't agree with that [Pickford's] way, everybody can see that but yeah it was just an unnecessary moment and movement."