The Catalan giants once again proved to be the best team that Spain have to offer last season, while Bilbao ended the campaign in eighth position - eight points off fourth-placed Valencia.
Thirteen wins, 14 draws and 11 defeats - that is how Bilbao performed in La Liga last season; a total of 53 points left them in eighth position, which means that they have missed out on European football for this campaign.
It will be just the second time since the 2013-14 season that Bilbao have not been present in either the Champions League or the Europa League. That was also the case last term after a disappointing 2017-18 campaign saw them finish in 16th, with European football almost acting as an unwanted distraction.
There is no getting away from the fact that it has been a disappointing couple of years for Bilbao when considering that they finished fourth, seventh, fifth and seventh between 2013 and 2017. They are a team which expect to play European football but just missed the cut for a Europa League spot last term.
That said, Bilbao deserve huge credit for consistently performing to a high standard considering their limitations in the transfer market. It has been a relatively quiet summer for the Basque outfit, who have managed to tie key player Inaki Williams to a new long-term contract amid reported interest from Manchester United.
It has been a busy summer in terms of volume of matches, though, with Bilbao starting their pre-season with a 6-1 win over Arenas Getxo on July 20. Since then, they have played on a further seven occasions, notably drawing with West Ham United and Roma in the early stages of August.
Bilbao's final pre-season game brought a 2-1 win over Mirandes on August 8, and now the Basque outfit have the small matter of an opener against the Spanish champions. Gaizka Garitano's side have a tough start to the campaign, considering that their next game is away to Getafe before hosting rivals Real Sociedad.
There is no question that the lack of European football will be a disappointment for the club. However, there will be no distractions for the team aside from the Copa del Rey. It will be up to the likes of Williams and Iker Muniain to score the goals once again, and it remains to be seen what type of campaign the fans can expect.
Bilbao have not actually beaten Barca in a home league game since December 2013. The Spanish champions are likely to be without a certain Lionel Messi for this encounter, though, and Garitano's side will certainly be looking to catch the champions off-guard in the opening fixture.
Recent form: WDWLDW
A record of 26 wins, nine draws and just three defeats saw Barca collect 87 points last season, which ultimately saw them finish 11 points clear of second-placed Atletico Madrid. It was not quite as comfortable as the previous campaign, although Ernesto Valverde's side were again far too strong for the rest.
It was not all sunshine and rainbows, though, with Barca incredibly being knocked out by Liverpool in the semi-finals of the Champions League, in addition to losing the Copa del Rey final to Valencia on May 25. In the end, just the league title will not be seen as a successful season due to the club's high standards.
It was always going to be an interesting transfer window for the club and they certainly did not disappoint - Antoine Griezmann was the big-money arrival, but deals for the likes of Frenkie de Jong and Junior Firpo have seen Valverde improve his squad in vital areas. Neymar could yet arrive from Paris Saint-Germain, although a lot would have to happen for the deal to go through before the start of September.
The likes of Malcom, Jasper Cillessen and Andre Gomes have all left Camp Nou, meanwhile, and it remains to be seen whether Philippe Coutinho departs before the end of the month. The club's business thus far has been impressive, and a number of their rivals will be looking on waiting to see whether Neymar arrives.
Barca have only actually played five times over the summer, with Chelsea beating them in their pre-season opener on July 23. Valverde's side have won all four of their matches since then, though, including back-to-back successes over Napoli in the United States, which followed a 2-1 success over Arsenal.
Griezmann, Luis Suarez and Ousmane Dembele all scored in the 4-0 win over Napoli last time out, and it would not be a surprise to see those three start against Bilbao as Messi is struggling to overcome a calf problem.
The likes of Atletico and Real Madrid will be looking to see where Barca could potentially drop points in the early weeks of the campaign - it seems unlikely against Bilbao, while the champions then face Real Betis and Osasuna before the September international break, which are games that Valverde's side will certainly expect to win.
It does appear to be the start of a new era for Barca, who look to have a squad capable of challenging for a treble this season. The Copa del Rey will again be third of their list of priorities, though, and the club would happily give up a challenge for the cup in order to concentrate on the league and Champions League.
Recent form: LWWWW
Bilbao boss Garitano has no major injury concerns heading into the contest, making it unlikely that there will be any major surprises when it comes to the starting XI.
As mentioned, Messi is unlikely to take part due to a calf problem. The attacker has not played any pre-season football following his involvement in the Copa America, making it incredibly doubtful that the 32-year-old will even make the bench for the clash at San Mames.
As a result, Griezmann is likely to join Dembele and Luis Suarez in the final third of the field, while De Jong could make his debut in the middle of the park.
The back four is expected to pick itself with Nelson Semedo joining Gerard Pique, Jordi Alba and Clement Lenglet, but Valverde does have decisions to make when it comes to the midfield three. Indeed, Sergi Roberto and Carles Alena are both pushing to start at the expense of Ivan Rakitic.
Athletic Bilbao possible starting lineup:
Herrerin; De Marcos, Alvarez, Martinez, Berchiche; San Jose, D. Garcia; Muniain, R. Garcia, Ibai; Williams
Barcelona possible starting lineup:
Ter Stegen; Semedo, Pique, Lenglet, Alba; De Jong, Busquets, Roberto; Dembele, L Suarez, Griezmann
Head To Head
Barca have won on four of their last five trips to San Mames in the league, though, and have not lost to the Basque outfit inside their own stadium since December 2013.
Bilbao, meanwhile, have won just two of their last 13 home La Liga fixtures against Barca.
We say: Athletic Bilbao 1-3 Barcelona
It is difficult to back anything other than an away win. Bilbao are a team capable of picking up big results in front of their own supporters. However, we expect the champions to triumph even without Messi.