The visitors are somehow still alive in terms of potential survival, but they are 17 points behind 17th-placed Valencia with six games left, while Almeria are 16th, two points ahead of 18th-placed Espanyol.
Match preview
Almeria will enter Tuesday's mammoth contest off the back of a 4-2 loss to the champions Real Madrid on Saturday afternoon, with the result leaving them on 33 points from 32 matches.
La Union are 16th in the table, just two points clear of 18th-placed Espanyol in what is a fascinating battle for survival, with Cadiz, Real Valladolid, Valencia, Espanyol and Getafe bidding to avoid dropping down to the Segunda Division for the 2023-24 campaign.
UDA have actually been relatively strong at home this season, picking up 26 points from 16 matches, but they have the second-worst away record in the division, only collecting seven points, which has been the main contributor to their problems this term.
Rubi's side will be aware of the importance of Tuesday's contest, and it would be hugely damaging for their confidence if they were unable to beat the team at the bottom of the division.
Almeria won the Segunda Division last season to secure a return to the top flight, and they are bidding to make it back-to-back campaigns at this level for the first time since 2015.
Elche, meanwhile, recorded easily their standout result of the season on Saturday, thumping Rayo Vallecano 4-0 to keep their incredibly-slim survival hopes alive.
Tete Morente, Lucas Boye, Fidel and Gerard Gumbau were on the scoresheet in a brilliant performance, with the result moving the basement side onto 16 points from 32 matches.
Mathematically, at this stage, Elche can still survive, but they are 17 points behind 17th-placed Valencia, so it is almost an impossible task, and their relegation would be confirmed on Tuesday evening if they fail to collect all three points against Almeria.
Los Franjiverdes will already be planning for next season in the Segunda Division, with their three-year stay at the top level set to be confirmed at some stage in the not too distant future.
Sebastian Beccacece's side will be looking to repeat their performance from Saturday against Rayo, but their away form has been so poor this season, picking up just six points from 16 matches, finding the back of the net on only nine occasions.
Almeria La Liga form:
D
W
L
L
W
L
Elche La Liga form:
L
L
L
L
L
W
Team News
Almeria will again be missing Diego Fuoli and El Bilal Toure for Tuesday's match through injury, but Srdan Babic is back after serving a suspension against the Spanish champions.
Head coach Rubi made a number of changes for the trip to Real Madrid, but the team's key players will be back in the side for this one, with Luis Suarez set to return at centre-forward.
There will also be recalls for the likes of Alejandro Pozo, Lucas Robertone, Leo Baptistao and Alex Centelles, while Babic is expected to return in the middle of the defence.
As for Elche, Omar Mascarell and Pedro Bigas remain major fitness doubts, while Jose Angel Carmona and Helibelton Palacios are definitely out of the game through injury.
There is every chance that head coach Beccacece will select the same XI that took to the field for the first whistle against Rayo, with Boye again leading the line.
Pere Milla started on the left on Saturday and that should again be the case here, with Morente and Fidel also set to provide support in the final third of the field.
Almeria possible starting lineup:
Martinez; Pozo, Chumi, Babic, Centelles; Melero, De la Hoz, Robertone; Baptistao, Suarez, Embarba
Elche possible starting lineup:
Badia; Josan, Magallan, Clerc, Blanco; Nwankwo, Gumbau; Morente, Fidel, Milla; Boye
We say: Almeria 1-0 Elche
This is a huge match at the bottom of the table, and those involved in the relegation battle will certainly be hoping for an Elche win. Almeria's home form this season has been strong, though, and we are expecting La Union to secure a vital three points, relegating Elche in the process.