Leganes looked as good as relegated when they lost 3-0 at home to Sevilla at the end of June, but Los Pepineros have been in brilliant form during the month of July.
Indeed, Javier Aguirre's side have picked up 10 points from their last four matches, beating Espanyol, Valencia and Athletic Bilbao in the process, to give themselves a chance of avoiding the drop.
As it stands, Leganes are 18th in the table, one point behind 17th-placed Celta, who will finish their campaign away to already-relegated Espanyol at the same time on the same night.
The fact that Madrid won the title on Thursday could help the home side here, but it is still a huge task against the champions, who have been simply sensational since returning to action in June.
Los Blancos actually ran out 5-0 winners in the reverse match at the Bernabeu earlier this season, but the points were shared in the corresponding game during the 2018-19 campaign.
Madrid's 2-1 win over Villarreal on Thursday secured their 34th La Liga title, and they actually sit seven points clear of second-placed Barcelona in the table, with the Catalan giants losing at home to Osasuna.
Zinedine Zidane's side have won all 10 of their league games since returning from the lockdown period, and they will be determined to make it 11 in a row on Sunday night.
The season is not finished for the capital giants after this weekend, though, as they have the small matter of the second leg of their last-16 Champions League clash with Manchester City to come on August 7.
Los Blancos have work to do in the European tie as they trail 2-1 from the first leg at the Bernabeu, but the capital giants will be full of confidence due to their stunning form over the last month.
Madrid have the best away record in La Liga this season with 37 points from 18 matches, while Leganes have the second-worst home record, which will not fill the home supporters with too much confidence.
Leganes La Liga form: LLWDWW
Real Madrid La Liga form: WWWWWW
Leganes will be without the services of Ruben Perez through suspension due to the yellow card that the midfielder picked up in the 2-0 win at Athletic on Thursday night.
As for Madrid, Marcelo is the team's only guaranteed absentee through injury, meaning that Zidane has plenty of decisions to make when it comes to his starting XI.
It seems unlikely that wholesale changes will be made, though, as Zidane will want to keep some form of consistency ahead of their huge Champions League clash with Man City next month, meaning that Welsh attacker Gareth Bale could again miss out on minutes.
Leganes possible starting lineup:
Cuellar; Ruibal, Bustinza, Tarin, Siovas, Rosales; Eraso, Amadou, Mesa, Gil; Guerrero
Real Madrid possible starting lineup:
Courtois; Carvajal, Varane, Ramos, Mendy; Valverde, Casemiro, Modric; Vinicius, Benzema, Asensio
We say: Leganes 0-2 Real Madrid
Leganes deserve huge credit for even giving themselves a chance of avoiding the drop, but we are struggling to see a home victory this weekend, even taking into account the fact that Madrid have already won the title. The capital giants have been so strong since the restart, and we are backing a routine away success here.