That run has seen the visitors drop to 17th spot in the Primeira Liga table, level on points with basement side Maritimo, while the hosts will be looking to close the gap between themselves and sixth-placed Vitoria de Guimaraes.
Santa Clara recently snatched a point in dramatic fashion at home to Tondela, as the visitors looked set to see out a 1-0 win with Os Acoreanos reduced to nine men.
They would go on to snatch a point in the dying embers though, as Yohan Tavares turned the ball into his own net in the 94th minute to surrender the Tondela lead.
However, they suffered an agonising defeat last time out, when they travelled to the Estadio do Dragao to take on defending champions Porto.
The hosts took the lead through Sergio Oliveira, but Carlos equalised from the penalty spot and the game looked set to finish 1-1 until Antonio Martinez bagged a winner in the 95th minute for Os Dragoes to take all three points and send Daniel Ramos's men home empty-handed.
Despite the heartbreak of conceding a late winner, Os Acoreanos should be encouraged by the performance which saw them hold the second-placed outfit for the majority of the game, providing solid foundations to build on as they go into the final straight of the campaign.
Ramos's men currently sit seventh in the Portuguese top flight, with just a three-point gap between themselves and sixth-placed Vitoria de Guimaraes, meaning a run of victories could see them break into the top six and bag an impressive league finish.
He will see Sunday as a great opportunity to return to winning ways and put more pressure on Vitoria, as they take on a Nacional side who have lost their last seven league games.
After six consecutive defeats, Nacional dismissed manager Luis Freire, who had secured promotion from the second tier last season, and brought in Manuel Machado for his fourth spell at the helm with the task of saving the club from the drop.
However, Machado had the worst possible start to his latest stint in the hot seat, as his side were thrashed 5-1 by fellow strugglers Portimonense.
That stretched their losing run to seven games in the top flight, a run which has seen them quickly drop into the relegation zone after they previously sat comfortably in mid-table under Freire in the first half of the campaign.
Hope is not lost for Os Alvinegros yet though, as they sit just one point behind Farense in the relegation playoff place and three points adrift of automatic safety.
If they are to salvage their season and avoid the drop, the Madeira outfit will need to quickly end the dismal run which has seen them concede 19 goals in seven games, starting with what would be an impressive result on Sunday.
Allano is expected to slot back into the front line alongside Crysan and Carlos, who took his tally to nine league goals for the season in the defeat to Porto.
Manuel Machado could look to make several changes to the Nacional side that was thrashed by Portimonense in his first game at the helm, with the likes of Kenji Gorre and Bryan Rochez looking to return to the starting side.
They will welcome centre-back Julio Cesar back to action, after he served a suspension last time out following a red card in their 2-0 defeat to Gil Vicente.
They should also be boosted by the return of winger Vincent Thill, after he missed the last game due to international duty with Luxembourg.
The line will be led by Brayan Riascos, who has netted 10 goals in all competitions so far this season.
Santa Clara possible starting lineup:
Marco; Ramos, Villanueva, Cardoso, Mansur; Morita, Lincoln, Nene; Allano, Crysan, Carlos
Nacional possible starting lineup:
Piscitelli; De Souza, Henrique, Cesar, Vigario; Borges; Thill, Bessa, Gorre, Rochez; Riascos
We say: Santa Clara 2-0 Nacional
Given their current form, it is difficult to predict anything other than an eighth consecutive league defeat for Nacional on Sunday.
Santa Clara should have more than enough to break through a defence which has shipped 18 goals in the last seven games, and we see them returning to winning ways with a comfortable home victory.