Rafa Benitez believes his players need to have a "must win" mentality if they are to maintain their position at the top of the Barclays Premier League.
The Spaniard thinks his side will have to claim three points from the bulk of their games this season if they are to clinch their first league title since 1990.
"It's clear that if you want to stay at the top of the table you must win nearly all of your games," said Benitez.
"We will try to do that even though we know it will be difficult. The type of games like we have this weekend are really important for the confidence of the team.
"If we can win here we will still be at the top of the table, everybody will be happy and we will be ready going into the next game.
"We have made a good start. Confidence is great – all the players are feeling like that, so we can play and win. But we must take one game at a time and not think too much about the future."
Liverpool have claimed 10 points from a possible 12 in the league so far, but Benitez knows his team will have to be on top form to maintain their unbeaten start at Fratton Park.
He said: "Portsmouth are a good team with an experienced manager. Their players know what to do. They can control games. We know they are very tough to play against from when we faced them in Hong Kong.
"They have some new signings who are playing really well. John Utaka is doing a good job right now and Kanu and Benjani are dangerous also."
Meanwhile, Benitez revealed that Steve Finnan, who pulled out of international duty through injury last week, will train with the first team this afternoon as he steps up his bid to face Portsmouth.
