Rayo are currently sixth in the La Liga table, boasting 34 points from their opening 23 matches, while Athletic sit ninth, just two points behind their opponents in this weekend's contest.
Match preview
Rayo have never finished higher than eighth in Spain's top flight, so the capital outfit are chasing some history this season, with an impressive campaign to date leaving them in sixth spot in the table.
Andoni Iraola's side have won nine, drawn seven and lost seven of their 23 matches this season to collect 34 points, but they are far from comfortable in that spot and are only actually four points clear of 11th-placed Girona on the same number of games.
Rayo's last victory in the league was at home to Almeria almost one month ago, drawing back-to-back fixtures against Getafe and Sevilla before suffering a 1-0 defeat away to Cadiz last time out.
Los Franjirrojos will be pleased to be back at home this weekend, having picked up 18 points from 11 matches in front of their own supporters, recording five victories in the process.
Rayo have lost three of their last four La Liga matches against Athletic, though, including a 1-0 defeat in the corresponding fixture during the 2021-22 campaign.
Athletic also beat Rayo 3-2 in the reverse match earlier this season, with Inaki Williams, Oihan Sancet and Nico Williams on the scoresheet for the home team at San Mames.
The Basque outfit will actually enter this match off the back of three straight defeats, including their last two in the league against Atletico Madrid and Girona.
Athletic were also beaten 1-0 by Osasuna on Wednesday night in the first leg of their Copa del Rey semi-final, with Abde Ezzalzouli's 47th-minute effort securing an advantage for the home side in Pamplona.
Ernesto Valverde's team have had mixed success on their travels this season, winning three, drawing three and losing five of their 11 league games to collect 12 points.
Athletic were eighth in Spain's top flight last season, while they have not finished in the top six since 2016, so it would certainly be a huge success if the club could secure European football for the 2023-24 campaign.
Rayo Vallecano La Liga form:
L
W
W
D
D
L
Athletic Bilbao La Liga form:
L
L
W
W
L
L
Athletic Bilbao form (all competitions):
L
W
W
L
L
L
Team News
Rayo have no fitness concerns ahead of their contest with Athletic, but the home side will be without the services of Alejandro Catena following his red card against Cadiz.
Catena's position in the middle of the defence is likely to be taken by Esteban Saveljich, while there could also be a spot in the starting side for Oscar Trejo.
A change of formation might see Sergio Camello operate as the lone centre-forward, with Raul de Tomas potentially dropping down to the bench following the loss at Cadiz.
As for Athletic, Yeray Alvarez is suspended following his booking against Girona, which is likely to open the door for Dani Vivian to feature in the middle of the defence.
Inigo Martinez played the full 90 minutes against Osasuna in the Copa del Rey after a lengthy period on the sidelines, and the centre-back will be hoping to keep hold of his starting role for this one.
Jon Morcillo and Ander Herrera remain on the sidelines, while Unai Simon is out with a muscular problem.
Head coach Valverde has decisions to make when it comes to the final third of the field, and Alex Berenguer could drop out to allow Nico Williams to support Gorka Guruzeta.
Rayo Vallecano possible starting lineup:
Dimitrievski; Balliu, Lejeune, Saveljich, F Garcia; Comesana, Valentin; Palazon, Trejo, Martin; Camello
Athletic Bilbao possible starting lineup:
Agirrezabala; De Marcos, Vivian, I Martinez, Yuri; D Garcia, Vesga; N Williams, Sancet, I Williams; Guruzeta
We say: Rayo Vallecano 1-1 Athletic Bilbao
This has all of the makings of a very interesting match, and cases can be made for both sides to pick up all three points. We are expecting a really close affair, though, ultimately settling on a 1-1 draw, which would not be the worst result in the world for either side at this stage of the season.