With only three points between eighth place and bottom spot, victory at the weekend could make a significant difference to their ambitions for 2021.
Having earned a return to Portugal's top flight, Nacional will be satisfied if they are able to keep their heads above water throughout this season.
While they will be content with 13th position at this stage, losing three games in a row means that there is now a bit of pressure on boss Luis Freire.
Although two of those defeats came against top-seven opposition, the first setback against bottom-placed Portimonense set the ball rolling for successive disappointments.
A home clash with Tondela is the ideal fixture for Freire and his squad to turn things around, but another defeat could leave the club in the bottom two of the table.
Tondela have not been faring much better than their hosts in recent matches, their only point in three matches coming from their latest outing against Moreirense.
Nevertheless, credit came their way when they suffered a 4-3 defeat at Porto earlier in the month, eventually losing out to the champions after holding a 2-1 advantage.
That result means that the positives will be taken from a third clean sheet in six matches being kept last weekend, and Pako Ayestaran will view this as an opportunity to further extend their defensive improvement.
Mario Gonzalez has scored three goals from four appearances this season, but the forward was forced off through injury during the early stages of the last match.
Nacional Primeira Liga form: DDWLLL
Nacional form (all competitions): WWLLLW
Tondela Primeira Liga form: WLWLLD
Tondela form (all competitions): WWLLLD
Having only lost out by a 2-0 scoreline at Porto, Ayestaran may opt against making changes to his Nacional XI.
Tondela will be without Joao Pedro after the midfielder was sent off in the stalemate with Moreirense.
Souleymane Anne is in line to take the place of Gonzalez in the final third.
Nacional possible starting lineup:
Guimaraes; Freitas, Pedrao, Kal, Vigario; Danilovic, Alhassan, Azouni; Camacho, Riascos, Gorre
Tondela possible starting lineup:
Niasse; Medioub, Tavares, Martinez; Bebeto, Grau, Augusto, Ferreira; Agra, Barbosa; Anne
We say: Nacional 1-1 Tondela
With these sides having recorded just four wins between them all season, you should not expect fireworks at either end of the pitch. With that in mind, we feel that a low-scoring draw is the most likely result in this encounter.