Having collected 35 points from as many matches, Rayo will begin matchday 36 in 16th position, while the visitors are languishing in 19th place with just 21 points to their name.
Match preview
After achieving 12th and 11th place finishes under Andoni Iraola, Rayo have experienced a drop-off in their first season without the Basque manager.
However, the team from Vallecas are still well set to extend their three-stay in the top flight after holding Valencia to a goalless draw to move five points clear of the relegation zone.
Rayo can secure survival with two matches left to play if they better Cadiz's result, with their relegation rivals set to travel to the Ramon Sanchez Pizjuan for a meeting with Sevilla.
Los Franjirrojos have lacked a cutting edge in recent weeks, having failed to find the net in five of their last six matches, including each of their previous three outings.
However, they have managed to score at least two goals in each of their last four games against Granada (W3, D1), helping them put together a 10-game unbeaten run in competitive head-to-head meetings (W8, D2).
After winning 2-0 in August's reverse fixture, a win on Wednesday would give Rayo their first league double of the 2023-24 season.
Last season's Segunda Division champions Granada will be back playing their football in the second tier next term after their relegation was confirmed with Mallorca's 1-0 victory over Las Palmas.
As a result, the Andalusian side knew their fate before they even took to the pitch for Saturday's tricky clash against the newly-crowned champions Real Madrid.
Unfortunately for Granada, a much-changed Real Madrid side showed little mercy as they produced a free-scoring display to condemn the Nazaries to a 4-0 defeat, representing their 22nd loss of the 2023-24 La Liga season.
Granada have shipped seven goals across their last two matches and 68 goals across their 35 league matches, leaving them with the second-worst defensive record in the top flight.
While a habit of leaking goals has contributed to their demise, Granada's woeful away form has also contributed to their immediate return to the second tier, with their 17 road trips producing three draws and 14 defeats.
Although they cannot salvage their La Liga place, Jose Ramon Sandoval's side will still be determined to claim their first away win of the season and their first competitive victory against Rayo in December 2013.
Rayo Vallecano La Liga form:
D
D
W
L
L
D
Granada La Liga form:
L
W
D
W
L
L
Team News
Rayo boss Inigo Perez will have the majority of his squad available for Wednesday's contest, although he is still without 20-year-old midfielder Diego Mendez.
Isi Palazon could be recalled to the starting lineup after he came off the bench to feature as a half-time substitute in Saturday's goalless draw with Valencia.
Perez may also be tempted to bring some fresh legs into midfield, with Unai Lopez in contention to start against Granada.
Meanwhile, Granada winger Kamil Jozwiak is unavailable for selection after sustaining a muscle injury in Saturday's defeat to Real Madrid.
Having missed the last three matches, midfielder Antonio Puertas remains a doubt for the midweek trip to Vallecas.
After serving a one-match suspension, Miguel Rubio is set to replace Kamil Piatkowski and partner Ignasi Miquel in central defence.
Rayo Vallecano possible starting lineup:
Dimitrievski; Balliu, Mumin, Lejeune, Espino; Valentin, Lopez; Palazon, Trejo, Garcia; Camello
Granada possible starting lineup:
Batalla; Mendez, Rubio, Miquel, Neva; Pellistri, Gumbau, Hongla, Melendo; Boye, Uzuni
We say: Rayo Vallecano 2-0 Granada
Rayo may have failed to win any of their last three matches, but Wednesday's game represents a golden chance to return to winning ways.