Lazio boss Edy Reja accepts Udinese are favourites to finish in the top four.
Lazio are just two points behind fourth-placed Udinese going into the last 90 minutes, but Reja fancies Udinese's chances.
"Nothing is decided yet, but Udinese need just a point on Sunday against a Milan side who have been celebrating for a while now," he told Lazio Style Radio.
While the Bianconeri entertain the League champions, Lazio need three points at already safe Lecce.
"We just have to go out there and win in the knowledge that we have already qualified for the Europa League.
"We've had an extraordinary season and finishing fifth is important for the Europa League as you miss out on the qualifying round.
"Lecce will want to end the season well in front of their home fans, but we have the need for a victory to give us a fifth place that we deserve."