The goalkeeper also believes Gareth Bale will play a vital role in Spurs' quest to secure Champions League football for next season
With just four games remaining, Spurs sit in fifth place, two points behind Arsenal who have played one match more, while Chelsea are three points ahead of Andre Villas-Boas' men in third.
"We want to be in the next Champions League but we know that if we don't get three points against Southampton our chance will be finished," said Lloris.
Last Sunday, Gareth Bale was named the PFA Player of the Year and Young Player of the Year following a talismanic campaign at White Hart Lane.
Lloris maintains the Wales international is vital to Spurs' top-four aspirations and believes the midfielder will play an influential role in the club's last four games of the season.
"Gareth Bale has had a great season for Tottenham and helped the team to be in this situation," said Lloris.
"I am sure he will help us realise this objective and we need him to win the next four games to finish in the top four."
Upon arriving at Spurs, Lloris initially faced strong competition from Brad Friedel but has since emerged as the club's first-choice goalkeeper, and the France international believes he has quickly adapted to the Premier League.
He added: "It was a big step in my career and it was very important to have a good adaptation in my life but also in football.
"I have enjoyed this season. It is true that it was not easy at the beginning, but after it was better."