The Reds will face the Portuguese giants in the first leg of their Champions League last-16 tie at the Estadio do Dragao hoping to reach the quarter-final stage of the competition for the first time in nine years.
Firmino scored his 20th goal of the season in Sunday's 2-0 win at Southampton, while strike partner Mohamed Salah is seeking his 30th goal this term, and the Brazilian is looking forward to meeting the 2003-04 Champions League winners.
"I don't know if they are going to be afraid or not but we will make their life difficult for sure. We will make them suffer," Firmino is quoted by the Liverpool Echo as saying.
"I'm going to do what I can to help Mo score goals and to help all the team. I also want to help myself to make a good season.
"Porto are an excellent team with tradition in the Champions League. It will be a tough game and we have to play our best. I know it's going to be physically and tactically a very strong game."
Firmino heads into the game with six Champions League strikes this season, with only Real Madrid star Cristiano Ronaldo ahead of him in the goalscoring charts.