The Spanish side have already secured a place in the knockout round, but they will be looking to beat Inter Milan to first place in order to secure a seeding in the last 16 draw.
No matter what happens here, if Real Sociedad can beat Inter on matchday six, then they are assured to win the group, thanks to what would then be a better head-to-head record.
Match or better Inter's result here though, and they will be in the ascendancy given their superior goal difference, as both sides sit on 10 points following three wins, and a draw against each other on matchday one.
One of those three wins came in the reverse in Austria on matchday two, before back-to-back wins over last season's quarter-finalists Benfica.
Imanol Alguacil's side were phenomenal in San Sebastian on matchday four as they tore Benfica to shreds in the first half, going in 3-0 up at the break, having also missed a penalty and had a goal chalked off by VAR.
Rafa Silva's consolation did little to dampen matters, and that was just the second goal that La Real have let in during the group stages, the joint-best record in the competition.
Home form across all competitions will give them confidence of another three points here, as they have lost just once at Anoeta all season - against Barcelona - and have won five of their last six.
Despite a 2-1 win over Sevilla at the weekend, thanks in part to Umar Sadiq's wonder goal, another top four finish already looks difficult for La Real, who will have been targeting fourth place again, but Girona's remarkable start make them the favourites to join the typical big three in the Champions League places.
Domestic form has also evaded Salzburg for much of this season, as they have not hit their usual lofty heights in the Austrian Bundesliga.
Salzburg currently find themselves level on points at the top with Sturm Graz, as 33 from a possible 45 is lower than what they have been accustomed to in the past decade.
A 3-2 win at Hartberg over the weekend was just the side's third win in 90 minutes over the last eight matches, and that has shown in Europe.
There were high hopes that Salzburg could spring a surprise in a difficult group and progress after winning away to Benfica on matchday one.
However, their following three group games have all ended in defeat, including at home to their upcoming opponents, and in back-to-back meetings with Inter, meaning third place is the best they can hope for.
Two draws in their final two games will guarantee a spot in the Europa League, while if they can simply better Benfica's result here, that will also be enough for Gerhard Struber's side.
Real Sociedad have a mostly fully fit squad to choose from, and they welcomed Kieran Tierney back to the matchday squad over the weekend after a brief absence saw him miss out on Scotland duty earlier this month.
A frustrating spell at the club looks set to continue for Andre Silva, who has played just 31 minutes since moving to San Sebastian, and he will join Carlos Fernandez and Martin Merquelanz on the sidelines.
Russian youngster Arsen Zakharyan is getting a more prominent role in the side, mainly as a substitute, while he did start in a recent league win over Almeria, but he is still facing huge competition for places with Takefusa Kubo, Brais Mendez and Ander Barrenetxea all in wonderful form.
Salzburg have a scarcely believable number of injuries heading into this clash, with up to 10 first-team players currently sidelined.
Sekou Koita and Fernando are also missing in attack, with Dijon Kameri and Maurits Kjaergaard rounding off the long injury list for Struber to deal with.
Real Sociedad possible starting lineup:
Alex Remiro; Elustondo, Zubeldia, Le Normand, Munoz; Brais Mendez, Zubimendi, Merino; Kubo, Oyarzabal, Barrenetxea
Red Bull Salzburg possible starting lineup:
Schlager; Dedic, Morgalla, Pavlovic, Guindo; Gloukh, Bidstrup, Capaldo, Sucic; Konate, Ratkov
We say: Real Sociedad 3-1 Red Bull Salzburg
Real Sociedad have been arguably the revelation of this Champions League campaign so far, sealing progression after just four games, and will hope for a favour from Benfica to boost their chances of winning the group heading into a matchday six encounter with Inter.
Salzburg dropping into the Europa League would give them a huge chance to be competitive, but it is likely to go down to the final matchday, as it will be a big ask for them to get a result here given Real's form.
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