Having secured qualification for the last 16 of Champions League, Barcelona's attention will now switch to improving their fortunes in the league.
Koeman's side have endured a very disappointing start to the season, picking up just 11 points in their first eight games. And with just one win in the last five in La Liga, it's vital they get a result here if they are to maintain a push for the league title.
Osasuna, somewhat surprisingly, have the same amount of points on the board as Barcelona this season.
They'll know they aren't playing the Barcelona of old, but this will be a tough game for them nonetheless, and one Koeman should really be looking to win.
Where to Watch on TV
When Is Kick Off? Sunday 29 November
What Time Is Kick Off? 13:00 (GMT)
Where Is it Played? Camp Nou
TV Channel/Live Stream? LaLiga TV
Barcelona will be without a few key players ahead of this tie. Having scored his first goal for the club during the week, Barça look set to be without Sergino Dest due to a muscle strain. If the American is sidelined then it's thought that Koeman will be forced to use Oscar Mingueza on the right, as they're already without Sergi Roberto due to slightly more long-term injury.
Both Roberto and Gerard Pique picked up injuries in Barça last La Liga fixture against Atletico Madrid, which they lost 1-0.
In brighter news for Koeman, winger Ousmane Dembele looks likely to return to the squad having missed the Dynamo Kyiv tie with a shoulder injury. Lionel Messi and Frankie de Jong should start having been rested midweek.
Osasuna also come into this clash with a few key players injured. Brandon, David Garcia, Chimy Avila and Adrian Lopez are all confirmed to be out, with Jonathan Calleri and Lucas Torro also doubtful.
Barcelona: Ter Stegen; Mingueza, Samuel Umtiti, Lenglet, Alba; De Jong, Pjanic; Coutinho, Messi, Dembele; Griezmann.
Osasuna: Sergio Herrera; Facundo Roncaglia, Unai Garcia, Raul Navas; Navho Vidal, Jon Moncayola, Oier, Juan Perez, Jony; Ante Budimir, Ruben Garcia.
Despite winning all their games in the Champions League this campaign, Barca's league form has been fairly uninspiring. Currently sat in 13th in La Liga, Messi and co. already find themselves a staggering 12 points behind surprise leaders Real Sociedad.
Their last three points came at home against Real Betis in a hugely entertaining 5-2 victory before the international break, but they have struggled since.
Equally, Osasuna are enduring a tough run of form and struggling for points this season. A lack of goals has certainly contributed toward his, having scored just nine goals this season thus far. Their last win came in October's 1-0 smash and grab against Athletic Club.
Dynamo Kiev 0-4 Barcelona (24/11)
Atletico Madrid 1-0 Barcelona (21/11)
Barcelona 5-2 Real Betis (7/11)
Barcelona 2-1 Dynamo Kyiv (4/11)
Alaves 1-1 Barcelona (31/10)
Osasuna 1-1 Huesca (20/11)
Sevilla 1-0 Osasuna (7/11)
Osasuna 1-3 Atletico Madrid (31/10)
Osasuna 1-0 Athletic Club (24/10)
Eibar 0-0 Osasuna (18/10)
Barca come into it as favourites, of course, but with the side not playing particularly well they'll need to up their game to avoid another disastrous result this weekend.