Ronald Koeman's side have picked up 12 points from their last four matches to move into third position in the table, but they are still 10 points behind leaders Atletico Madrid, who also have a game in hand.
Barca have not been without their problems this season, but the Catalan giants now have their sights on second-placed Real Madrid in Spain's top flight, having won their last four in the league against Huesca, Athletic Bilbao, Granada and Elche during a strong run of form.
Koeman's side are just three points behind the reigning champions in the table, but as mentioned, they sit 10 points off leaders Atletico, who also have a game in hand, which is an indication of the capital outfit's strength at the summit heading into the business end of the season.
Barca lost 3-2 to Athletic in the final of the Spanish Super Cup on January 17 but recorded a 3-2 victory over the same opponents in the league when they locked horns on January 6.
As well as four straight league victories, the Catalan giants also progressed to the quarter-finals of the Copa del Rey on Wednesday night courtesy of a 2-1 victory over Rayo Vallecano, with Lionel Messi and Frenkie de Jong scoring in the latter stages of the contest at Estadio de Vallecas.
Barca will be determined to continue their strong domestic form but will also certainly have one eye on their upcoming Champions League last-16 clash with Paris Saint-Germain.
As mentioned, Athletic beat Barca 3-2 in the final of the Spanish Super Cup on January 17, with Inaki Williams scoring what proved to be the winner on a famous night for the club in Seville.
Like their opponents here, Los Leones have also progressed to the quarter-finals of the Copa del Rey, recording a 2-1 victory over Alcoyano on Thursday night to advance.
Marcelino's side have actually won each of their last five games in all competitions since the 3-2 loss to Barca in the league, including a 5-1 home success over Getafe in Spain's top flight last weekend.
A record of 24 points from 19 matches has left Athletic in ninth position in the table, just four points off seventh-placed Granada, and they will certainly enter this weekend's contest in a confident mood.
Barcelona La Liga form: WDWWWW
Barcelona form (all competitions): WWLWWW
Athletic Bilbao La Liga form: WDLWLW
Athletic Bilbao form (all competitions): LWWWWW
Barca will be without the services of Sergio Busquets through suspension, meaning that there could be a spot in the middle of the park for Miralem Pjanic, who has struggled for action since arriving last summer.
There will be changes from the side that started against Rayo in the Copa del Rey, with Marc-Andre ter Stegen, Sergino Dest, Jordi Alba and Ousmane Dembele in line to return, but Antoine Griezmann should keep his spot alongside Messi in the final third of the field.
Barcelona possible starting lineup:
Ter Stegen; Dest, Araujo, Lenglet, Alba; De Jong, Pjanic, Pedri; Griezmann, Messi, Dembele
Athletic Bilbao possible starting lineup:
Simon; Capa, Alvarez, Nunez, Berchiche; De Marcos, Vencedor, D Garcia, Muniain; Williams, R Garcia
We say: Barcelona 2-1 Athletic Bilbao
Athletic's recent form cannot be ignored, and there is no question that the visitors will arrive at Camp Nou in a confident mood following five straight wins. Barca's form has also been impressive, though, and we just fancy Koeman's side to edge a tight contest on Sunday night.