It may be Marcelino's first game in charge of Athletic but the former Valencia boss faces an unwanted record if Athletic lose here. None of Athletic's last five managers have lost on their debut for the club since Mane in 2006. What more can the Basque side offer here to test Barca further?
Barca have cruised here despite facing the setback of Williams' early goal. Athletic started the game at a frightening pace until Pedri levelled for Barca 15 minutes in. Since then the hosts have been quiet, allowing Messi to give Barca the lead. More to come!
45' + 2' HALF-TIME: ATHLETIC BILBAO 1-2 BARCELONA
45' There'll be two added minutes at the end of this half.
44' Athletic have done precious little in an attacking sense since conceding an equaliser. Marcelino needs more from his team in the second half.
42' Barca look comfortable as we approach half-time but they'd like another goal. Messi gets a cute pass from Griezmann and fires wide of the right-hand post.
40' Barca go looking for a quick third goal. Griezmann unleashes a venomous shot from the left of the box that Simon pushes away. Dembele stretches but can't quite reach it to place into the net.
39' Messi has been directly involved in 24 goals against Athletic in 26 La Liga games now. He'd gone three games without scoring against them prior to his goal here.
37' Griezmann wins a free-kick down the left as he's brought down by Williams. Barca can't create very much from the free-kick.
35' Dest positions himself well to get rid of Capa's pacy low cross from the right. Muniain was lurking at the far post.
34' Barca have overtaken Athletic in shots now - it's five to the visitors and four to the hosts. Athletic haven't had a shot since Barca equalised.
33' Barca knock the ball around patiently outside Athletic's box, trying to craft a decent opening. Dembele cuts inside from the right and curls an effort towards Simon. The Athletic keeper can't hold it at first but soon controls it at the second attempt.
30' Berchiche pulls up with a thigh strain after beating Dembele near the touchline. The left-back looks in some discomfort. He'll have to be replaced.
28' Simon rushes out of his goal to prevent Messi from latching onto Dembele's throughball. It's a good game, this.
26' Berchiche's low cross from the left isn't convincingly cleared by Barca's defenders. Athletic's pace in forward areas is continuing to worry the visitors.
24' Messi gets caught offside from Busquet's pass and Athletic have the chance to go upfield for the first time in a while. Garcia is frustrated as he challenges for a high ball with Busquets and gives away a free-kick.
22' Barca are starting to dominate proceedings now. Alba has a low effort saved from the left of the box. It's another Barca corner which Athletic see off.
20' Athletic are having to defend for the moment. Garcia tugs on de Jong's shirt and gives away a foul in the centre of the pitch.
18' We've had seven shots in the opening 15 minutes of this game - four for Athletic and three for Barca. It bodes well for the rest of the match.
16' Barca are starting to settle after that frantic start. The visitors win a corner down their left off Capa. Athletic clear. Dembele is caught offside from Messi's throughball.
13' Dembele receives a pass from Messi and lets rip from the right edge of the box, inspiring Simon to tip it away. Athletic survive the resulting Barca corner.
12' Barca are just asking for trouble if they continue to play this high up the pitch. Williams gets in behind the visitors' defence again, firing straight at ter Stegen. It's a warning that more is to come from Athletic.
11' Athletic's captain Munain, playing on the left flank, has a pop from a tight angle. It's blocked by a Barca defender.
9' There's a brief chance for the players to take a breath as Pedri is fouled by Garcia. There's no way the game can stay at this speed for 90 minutes.
7' What a pace this game has started at. Dest gets on the end of Griezmann's pass and fires towards goal, forcing a save from Athletic's goalkeeper Simon. Barca take the corner and Lenglet is caught offside when Dembele eventually sends the ball in.
5' Athletic have really raced out of the traps here. Their left-back Berchiche races into the box on the counter-attack after a Barca attack breaks down and lashes a shot into the side netting. It could be 2-0 already.
1' We're underway here in Bilbao!
The two sides are out on the San Mames pitch. Athletic are wearing their usual red and white striped shirts and black shorts. Barca are in their yellow away strip.
Athletic have lost just one of their last four La Liga games against Barcelona and are unbeaten in the sides' last two meetings here at San Mames. However, Athletic haven't gone three games in a row without losing against Barca since 2013. Barcelona have lost just one of their last 17 visits to Basque sides though. Will Barca make it three away wins in a row?
There's just the one change to Athletic from their 1-0 win over Elche as Capa starts at right-back. Berenguer drops to the bench. Barca make a single change too from their away win over Huesca as Griezmann starts ahead of Braithwaite.
SUBS: Riqui Puig, Junior Firpo, Miralem Pjanic, Samuel Umtiti, Konrad De la Fuente, Trincao, Inaki Pena, Neto, Martin Braithwaite, Oscar Mingueza.
BARCELONA (4-3-3): Marc-Andre ter Stegen; Sergino Dest, Ronald Araujo, Clement Lenglet, Jordi Alba; Frenkie de Jong, Sergio Busquets, Pedri; Antoine Griezmann, Lionel Messi (c), Ousmane Dembele.
SUBS: Inigo Vicente, Ibai Gomez, Dani Garcia, Mikel Balenziaga, Asier Villalibre, Kenan Kodro, Oihan Sancet, Jon Morcillo, Inigo Cordoba, Inigo Lekue, Jokin Ezkieta, Alex Berenguer.
ATHLETIC BILBAO (4-4-2): Unai Simon; Ander Capa, Unai Nunez, Inigo Martinez, Yuri; Oscar De Marcos, Mikel Vesga, Unai Vencedor, Iker Muniain (c); Inaki Williams, Raul Garcia.
Athletic, meanwhile, are under new management after a weekend win against Elche was not enough to save Gaizka Garitano's job. It's Marcelino's first job since leaving Valencia in September 2019. No doubt a victory for the hosts here would be a great start to their new era.
Barcelona arrive in Bilbao looking to lift themselves to third in La Liga. Ronald Koeman's side sit fifth currently and are way off the pace in the title race behind Atletico Madrid and Real Madrid. A win here would mark a tentative return to more familiar territory.
Hello and welcome to our live text commentary of this La Liga match between Athletic Bilbao and Barcelona at San Mames Stadium.