The home side have lost back-to-back matches and are one place above the relegation zone, seven points better off than opponents Leganes.
Two defeats in a row without scoring - against Osasuna and Sevilla - has increased the pressure on Eibar ahead of this massive six-pointer.
Los Armeros have flirted with relegation all season and are still fighting for their survival with four games to go, including a trip to bottom side Espanyol at the weekend.
Jose Luis Mendilibar will know the importance of picking up a positive result in Thursday's clash, with one more win surely enough to stave off relegation for good.
Leganes are glad to still be in with a shot of survival thanks to a 1-0 win over Espanyol on Sunday, with Jonathan Silva scoring the only goal at the RCDE Stadium.
That brought an end to a six-game winless streak in which Los Pepineros collected only two points from the 18 on offer.
Javier Aguirre's side still face a huge task if they are to climb out of the relegation zone, where they have spent the entire campaign.
Only a victory will do on Thursday, with the gap on Eibar closing to four points with a win at Ipurua Municipal Stadium.
Eibar tend to do well in this fixture, though, having won their last three La Liga home games against Leganes without conceding a single goal.
However, Low Armeros have only won one of their last five home matches - 1-0 against Valencia in June - while Leganes have taken four points from their last three away games.
Eibar's La Liga form: DDWWLL
Leganes' La Liga form: LDDLLW
Fellow forward Kike Garcia is expected to start in attack and will be looking to make it four goals in four games against Leganes.
Ibrahim Amadou is the player most likely to make way from midfield to accommodate Mesa's return.
Eibar possible starting lineup:
Dmitrovic; Correa, Burgos, Bigas, Cote; Leon, Diop, Exposito, De Blasis; Charles, Garcia
Leganes possible starting lineup:
Cuellar; Bustinza, Awaziem, Siovas; Ruibal, Mesa, Perez, Silva; Rodrigues, Aviles; Guerrero
We say: Eibar 2-1 Leganes
It is all or nothing for Leganes as they quite simply need to win this game if they are to have any chance of staying up. That could work in Eibar's favour and we are tipping the hosts to edge Thursday's clash.