The 26-year-old scored the Reds' first, third and fifth goals in an impressive counterattacking performance from Jurgen Klopp's side.
While obviously impressed by his teammates goalscoring exploits, Milner also chose to recognise Mane for his tireless effort off the ball.
Milner told BT Sport: "Sadio Mane does his job and does a great job for the team. People see his flair and the goals that he scores but he does a great job working for the team.
"Porto are a very good side. It's a tough place to come, you could see the crowd and the way they were even at the end.
"We wanted to keep a clean sheet and with the players we have we always have the chance to score an away goal. I thought we could have scored more."