The Blues are currently seventh in the table and two points behind the top six, while L'Eivissa are 14th and have secured a comfortable mid-table finish in their first-ever season at this level.
Match preview
Six consecutive wins in late March and April appeared to have put Real Oviedo in a strong position to finish in the playoffs, but it is now out of their hands following a run of three games without a victory.
A 2-1 defeat to Las Palmas last weekend - their first loss since the start of March - was particularly crushing, as it meant that their opponents leapfrogged them into the top six. A win would have secured Oviedo a playoff spot.
It means that Jose Angel Ziganda's side must win on Sunday and hope that either sixth-placed Las Palmas lose away at Sporting Gijon or fifth-place Girona lose away at Burgos, as they are inferior to both teams in terms of head-to-head points.
Oviedo are searching for a return to La Liga for the first time in 21 years and this is their seventh consecutive season in the second tier - they have never made the playoffs before.
The Blues have the third-best defence in the Segunda Division and have only suffered two defeats at home all season. Only top-of-the-table Eibar have lost fewer games than them overall, but Ziganda's team have been guilty of drawing too many games and a point will not be enough on Sunday.
Ibiza were only founded in 2015, but three promotions in five years earned them a place in the second tier this season and they have performed admirably - they could still finish as high as 10th.
Paco Jemez replaced Juan Carlos Carcedo in the dugout in December and if the season had started when he took over, Ibiza would be just outside the playoffs.
However, L'Eivissa are finishing the campaign poorly. They have recorded just one win in their last six matches and a 2-1 defeat to Real Valladolid last weekend meant they lost back-to-back games for the first time under Jemez. Meanwhile, they have suffered six defeats in their last eight away games.
The two clubs met for the first time ever earlier in the season, with Oviedo's Gaston Brugman cancelling out Javi Lara's opener for Ibiza in a 1-1 draw.
Real Oviedo Segunda Division form:
UD Ibiza Segunda Division form:
Team News
Real Oviedo will be without Pierre Cornud after the left-back was sent off in the closing stages of the defeat to Las Palmas last weekend.
Samuel Obeng could be recalled to the starting lineup having dropped to the bench last weekend. He has scored in both of his last two starts.
Borja Baston has scored 20 goals so far this season and is only two behind Segunda Division top scorer Cristhian Stuani.
Ibiza also had a player sent off last weekend and will be missing Manu Molina following his two yellow cards before half-time against Real Valladolid.
35-year-old David Morillas and 36-year-old Javi Lara will likely start on their final appearances for the club.
Ibiza have severely missed Leeds United loanee Mateusz Bogusz in the second half of the season after he suffered an anterior cruciate ligament injury in January.
Real Oviedo possible starting lineup:
Femenias; Isaac, Costas, Calvo, Mossa; Sangalli, Luismi, Brugman, Sanchez; Baston, Obeng
UD Ibiza possible starting lineup:
Parreno; Cifuentes, Goldar, Ibiza, Morillas; Lara, Appin; Nono, Zenitagoia, Herrera; Guerrero
We say: Real Oviedo 2-0 UD Ibiza
Ibiza have nothing left to play for and have a poor recent away record anyway, so Real Oviedo should ease to victory here as long as they do not let what is at stake distract them. Then it will be down to other results to decide whether they will get a shot at promotion.