The Yellow Submarine, who beat Red Bull Salzburg 2-0 in the Europa League on Thursday, are currently sixth in Spain's top flight, eight points above 10th-placed Athletic, who have a game in hand.
Athletic will be aiming to make it back-to-back victories in the league, having recorded an impressive 4-0 win away to Cadiz on Monday night, with Alex Berenguer netting a brace for the Basque outfit.
Marcelino's side cannot afford to become distracted in Spain's top flight as they are only five points behind seventh-placed Real Betis and will be eyeing a potential Europa League finish this term.
However, the club will certainly be thinking about the Copa del Rey as they will face Levante in the second leg of their semi-final on March 4, with the tie delicately poised at 1-1 from the first leg.
Athletic will also take on Real Sociedad in the final of the 2020 competition at the start of April, with the match being postponed last year due to the coronavirus outbreak.
Los Leones recorded a 1-0 win over Villarreal when the two teams locked horns in the corresponding match last season, while they held the Yellow Submarine to a 1-1 draw in the reverse game back in December.
Villarreal, as mentioned, will enter Sunday's clash off the back of an impressive 2-0 win over Salzburg in the first leg of their last-32 Europa League clash on Thursday evening.
Villarreal's league form has tailed off, though, having picked up just four points from their last five matches, and they suffered a 2-1 home defeat to Real Betis last weekend.
Unai Emery's side have not actually triumphed in the league since a 4-0 success at Celta Vigo on January 8, with the disappointing run seeing them drop behind Real Sociedad into sixth position in the table.
El Submarino Amarillo are only two points behind Sociedad, though, and have only lost three of their 23 league matches this season, which is the second-best record in the division behind Atletico Madrid (1).
Athletic Bilbao La Liga form: WLWLDW
Athletic Bilbao form (all competitions): WLWDDW
Villarreal La Liga form: WDDDDL
Villarreal form (all competitions): WDLDLW
Athletic will be without the services of Unai Nunez and Mikel Vesga this weekend through suspension, with both players picking up yellow cards in the win over Cadiz last time out. As a result, Inigo Martinez should return in the middle of the defence, while Dani Garcia is expected to replace Vesga.
Peru Nolaskoain is still unavailable through injury, but the Basque side are otherwise in excellent shape, meaning that head coach Marcelino has plenty of options for change.
Oscar de Marcos had been operating on the right of midfield, but Berenguer scored twice in the win over Cadiz and should therefore retain his spot alongside Inaki Williams, Iker Muniain and Raul Garcia in attack.
Athletic Bilbao possible starting lineup:
Simon; Capa, Alvarez, Martinez, Berchiche; Berenguer, Lopez, D Garcia, Muniain; R Garcia, Williams
Villarreal possible starting lineup:
Asenjo; Pena, Albiol, Torres, Pedraza; Parejo, Capoue, Trigueros; G Moreno, Alcacer, M Gomez
We say: Athletic Bilbao 1-1 Villarreal
This is a very, very difficult match to call as both sides will feel that they can hurt the other in the final third of the field. Athletic have had much longer to prepare for this contest and should have an advantage, but Villarreal are tough to beat so we have settled on a low-scoring draw at San Mames.