Lazio coach Edy Reja has told his players to hold their nerve and focus on themselves rather than others when they host Inter Milan tomorrow night.
The Biancoceleste must win their final game of the campaign and hope Udinese - currently two points ahead - lose at Catania if they are to finish in third place and qualify for next season's Champions League.
Should Lazio, who are fourth, end level on points, Udinese would qualify for Europe's premier club competition as they have a better head-to-head record against the Romans.
Reja said: "If we play as we know how then we will be fourth and only then will we see what happens at Catania.
"We are playing in front of our fans and this is a very important game for us.
"We will have to give our all and then see where that leaves us.''
Lazio, who beat Atalanta 2-0 last time out, have lost just three times at then Stadio Olimpico this season.
However, the Romans will be without seven injured players, including captain Tommaso Rocchi, as well as goalkeeper Federico Marchetti and defender Andre Dias, both suspended.
The only consolation for Reja is that German forward Miroslav Klose, who is Lazio's top scorer with 13 goals, has recovered from a thigh injury that has kept him out of action since March and will feature on Sunday.
Rivals Inter travel to the Stadio Olimpico for Sunday's crunch match buoyed by last weekend's 4-2 triumph over AC Milan.
That result left Inter one point behind Lazio and level on 58 points with fifth-placed Napoli, who host Siena this weekend.
More importantly, it ensured Inter will finish at least sixth in Serie A while it also kept their faint hopes of finishing third alive.
For that to happen, the Nerazzurri must beat Lazio and hope Udinese and Napoli lose their respective games on Sunday
"We want to win and live in hope,'' Inter striker Diego Milito said. "We are still in there.''
Inter have lost just one of their eight games under coach Andrea Stramaccioni, a 3-1 defeat at Parma on May 2.
Luca Castellazzi will replace the suspended Julio Cesar in Inter's goal.