Both sides have struggled since securing automatic promotion from the npower Championship last season and sit in the bottom three heading into the St Mary's clash.
Saints are a place, and three points, better off and know that victory could propel them out of the relegation zone. The last time Saints faced a fellow struggler they beat QPR 3-1 in west London and Fonte believes such experience stands them in good stead.
"It is a massive game for both of us," the Portuguese defender said. "We are aware of the pressure. It is going to be an energetic game, tough for both of us, but we look forward to it.
"We have been preparing ourselves very well this week and we have our game plan and we will try and win the game on Saturday. It is a lot of pressure [in these kind of games]. You have to try and stay calm and know your game plan well, know your job.
"You know what you have to do and as a team, work hard to get the better of them. It is as simple as that."
Sometimes the quality of football can be sacrificed in such high-pressured matches, but that is not something Fonte expects from Southampton.
"The attitude has to be 100 percent but our philosophy is to play attractive football, to play a passing game," he said. "That's what we've been doing for the last three years. We have to do continue that. That's what we train every week to do.
"The players that we have they like to dribble, they like to pass it around and create chances like that, although we always have the option of going direct to Rickie Lambert, which is a great way out for us.
"But we like to play attractive football, as I said, and pass it around so we will try and do that."