Ernesto Valverde's side beat Chelsea 3-0 in the Champions League on Wednesday to take their place in the last eight of the competition and the Bluagrana were paired with Roma in Friday's quarter-final draw.
In the Primera Division, the Blaugrana remain unbeaten with 72 points from their 28 games, having won 22 and drawn six so far to lead second-placed Atletico by eight points with 10 rounds left.
Here, Goal takes a look at everything you need to know ahead of Saturday's match against Athletic...
Nelson Semedo is still out with a hamstring injury, while Sergio Busquets is also sidelined after suffering a hairline fracture in one of his toes against Chelsea.
Sergi Samper is out with a long-term problem. The midfielder was on loan at Las Palmas, but damaged ankle ligaments in a game against Eibar in January and has returned to Barcelona for the rest of the season in order to recover and receive treatment.
Denis Suarez is also sidelined.
Luis Suarez misses out through suspension after picking up his fifth yellow card of the season in La Liga last weekend as Barca beat Malaga 2-0.
Barcelona potential starting line-up
With Luis Suarez suspended, Paco Alcacer is in line for a rare start for Barcelona in attack alongside Lionel Messi.
In midfield, Andre Gomes could come in for the injured Busquets, while Philippe Coutinho is set to start after resting on Wednesday, given that he is cup-tied for the Champions League.
After his impressive performance against Chelsea in which he scored his first Barca goal, Ousmane Dembele is set to keep his place on the right.
Athletic team news
In La Liga, this has also been an inconsistent season for the Basque outfit, down in 12th place with just 35 points from their 28 games.
Mikel Balenziaga could return at left-back against Barca, but winger Iker Muniain is sidelined, while midfielder Mikel Rico and defender Yeray Alvarez are doubtful.
TV channel & kick-off time
Barcelona versus Athletic kicks off at 16:15 local time on Sunday and will be broadcast live in the UK (United Kingdom) on Sky Sports Football (via the red button) and Sky Sports Mix from 15:10 GMT.
In the United States, the game can be watched live on television on beIN SPORTS and kicks off at 10:15 ET.
Best Opta match facts
Barcelona have won their last eight league games against Athletic, keeping a clean sheet in six of these matches. They have never won nine games in a row against the Basques in the top flight.
Athletic Club have lost 60 away games against Barcelona (of 86 in total) in La Liga; more than against any other team.
Lionel Messi has scored 16 goals in his 18 games at the Camp Nou against Athletic in all competitions.
Aritz Aduriz has scored eight goals against Barcelona for Athletic Club in all competitions, but only two of those have come at Camp Nou.
No La Liga defender has provided more league assists than Jordi Alba this season (seven, level with Eibar's Jose Angel).