Gaizka Garitano's side will enter this weekend's contest off the back of a 2-0 home win over Levante, while Osasuna shared the points with Eibar in their last match.
Osasuna finished 10th in La Liga last season on their return to this level of football and were ultimately just four points off the Europa League spots, impressing many with their performances throughout the campaign.
Jagoba Arrasate's team have made a solid start to the new season, picking up seven points from their five matches to sit 11th in the table, boasting the same number of points as Barcelona, although the Catalan giants have only played four times this term.
Osasuna lost back-to-back games against Getafe and Levante towards the end of September but beat Celta Vigo on October 4 before sharing the points away to Eibar last weekend.
Los Rojillos will be determined to pick up a positive result on Saturday considering that three of their next five in La Liga are against Atletico Madrid, Sevilla and Barca during a tough run of matches.
An inconsistent start to the campaign has seen Garitano's side win two but lose three of their first five matches, leaving them in 14th position in the table, just two points outside of the relegation zone.
Interestingly, the home team has not actually won this particular fixture since August 2013; four of the last five matches have brought away victories, with Athletic recording a 2-1 win in the corresponding game last term.
The eight-time La Liga champions finished 11th in Spain's top flight last season, and it is difficult to imagine them pushing for a European spot in 2020-21 due to the strength of the sides around them.
Osasuna La Liga form: WLLWDD
Athletic Bilbao La Liga form: LWLLW
It would not be a surprise to see the same XI that lined up against Levante take to the field for this match, with Williams again being supported by Berenguer, Raul Garcia and Iker Muniain in the final third.
Osasuna possible starting lineup:
Herrera; Roncaglia, Aridane, D Garcia, Perez; R Garcia, Jony, Oier, Barja; Gallego, Adrian
Athletic Bilbao possible starting lineup:
Unai; Capa, Yeray, Martinez, Balenziaga; D Garcia, Lopez; Berenguer, R Garcia, Muniain; Williams
We say: Osasuna 1-1 Athletic Bilbao
Athletic will be boosted by the fact that Osasuna are missing some key players, but we are finding it difficult to back the Basque outfit with any real confidence due to their inconsistency. Osasuna have picked up four points from their last two league matches, and we are expecting a low-scoring draw in this contest.