The Catalan giants thrashed Villarreal 4-0 in their first competitive match of the Koeman era, but Celta have also started strongly and boast an impressive record in this fixture.
For all the talk of Barcelona being in crisis, with key men departing and Lionel Messi being denied the chance to do the same, they looked very good in their opening league outing.
It was near enough the perfect response from Barca to their critics on the back of a tough couple of months, but this will be a far tougher test for last term's runners-up.
Celta are unbeaten in their opening three matches, beating Valencia 2-1 at home in between a couple of draws away at Eibar and Real Valladolid.
That makes it four games without defeat overall in the top flight, which is just one short of their longest such run in the last three seasons.
More than that, though, it is their record against Barca at Balaidos that makes this stand out as a possible banana skin fixture for the visitors.
Celta are unbeaten in their last five league meetings with Thursday's opponents on home soil, winning three and drawing two of those.
It is Barca's longest current winless away run against any opponent in La Liga, stretching back to Luis Enrique's time in charge five years ago.
However, Barcelona have won their last three away La Liga games and could win four on the spin for the first time since January 2019 with victory in midweek.
Celta Vigo La Liga form: DWD
Barcelona La Liga form: W
Barca's first-choice goalkeeper Marc-Andre ter Stegen is out for another couple of months with a knee injury, meaning that Neto is enjoying an extended run between the sticks.
Koeman otherwise has a full squad to choose from, but changes are unlikely on the back of the routine win over Villarreal.
Messi, who has scored 11 goals in 16 La Liga appearances against Celta, should get the nod in the same front four - and indeed XI - that started last time out.
Santi Mina will be hoping for a recall in attack alongside Aspas, who has scored seven goals in his last nine La Liga appearances against Barcelona.
Celta Vigo possible starting lineup:
Villar; Aidoo, Murillo, Araujo; Vazquez, Tapia, Yokuslu, Olaza; Mendez; Mina, Aspas
Barcelona possible starting lineup:
Neto; Roberto, Pique, Lenglet, Alba; Busquets, De Jong; Griezmann, Coutinho, Fati; Messi
We say: Celta Vigo 1-2 Barcelona
Only at the Santiago Bernabeu (seven) have Barcelona lost more games away from home in La Liga than at Balaidos this century.
Celta have started the campaign brightly and have a solid overall home record, but Barca looked impressive in their opening game and have won three away league matches in a row.
With that in mind, we are going with a narrow away win on Thursday.