The visitors are sat 19th in the table, but level on points with Metz above them, whilst the hosts have had a far more comfortable run-in up in the top half.
Match preview
Nantes can be pleased with a first top-half finish for four years to go with their first piece of silverware since 2005 having won the Coupe de France a fortnight ago.
There was no sign of any hangover from their cup exploits when they impressively got the better of podium-chasing Rennes 2-1 a few days later, but they were unable to keep up that momentum last weekend.
Their game away at Lyon looked to be heading for a dull 1-0 win for the hosts, courtesy of an early Moussa Dembele header, only for four goals in the final quarter of an hour to turn the match into a five-goal thriller.
First, Lucas Paqueta extended Les Gones' lead in the 78th minute, then Quentin Merlin halved the deficit three minutes later, another four minutes saw another goal - this time from Tete to restore the two-goal advantage - before Wylan Cyprien's consolation in stoppage time.
Antoine Kombouare's side have been far stronger on home soil than on the road so will be confident of finishing the campaign on a positive note, even with so much at stake for the visitors.
Saint-Etienne appeared to be pulling off a miraculous escape under new manager Pascal Dupraz when they put together an impressive string of results between January and March.
Across eight games, they secured four wins and three draws - including a crucial 1-0 victory over fellow relegation candidates Metz - to move themselves out of the bottom two for the first time since the early weeks of the season.
The wheels then fell off, however, as they let leads slip in what would prove to be a 4-2 loss against Marseille and, more painfully, a 6-2 defeat to Lorient.
A win over Brest and a draw with Bordeaux left them with hope for the run-in, but four consecutive defeats have now left them with their survival out of their own hands.
Last weekend's 2-1 loss at home to Reims allowed Metz to move up to 18th courtesy of a narrow win, and the pair will now go into the final game level on points - with six goals separating them on goal difference - fighting over the relegation playoff spot of 18th place.
Nantes Ligue 1 form:
Nantes form (all competitions):
Saint-Etienne Ligue 1 form:
Team News
Nantes' two long-term absentees Pedro Chirivella and Charles Traore will end the season in the treatment room as expected, but Kombouare's side are otherwise in good shape ahead of Saturday's clash.
There may be some rotation as the campaign draws to a close, giving a few less-familiar faces a run-out, but one man who will surely play some part is top scorer Randal Kolo Muani ahead of his free transfer to Eintracht Frankfurt this summer.
The visitors have no such luxuries in being able to give the B-team a chance or allowing players a farewell, with so much left to play for.
They do, though, have the luxury of a near-clean bill of health, with Falaye Sacko the only confirmed absence.
A 5-4-1 formation should include Ryad Boudebouz at centre-forward, with Denis Bouanga and Arnaud Nordin likely supporting from the wings.
Nantes possible starting lineup:
Lafont; Corchia, Castelletto, Pallois, Merlin; Moutoussamy, Cyprien; Coco, Blas, Simon; Kolo Muani
Saint-Etienne possible starting lineup:
Bernardoni; Macon, Sow, Moukoudi, Mangala, Silva; Nordin, Camara, Youssouf, Bouanga; Boudebouz