The hosts have won their last five games in all competitions, beating Villarreal 1-0 on the weekend, while the visitors protected their six-point advantage at the top of the Moldovan Super Liga with a 1-0 win over bottom club Dinamo-Auto.
Match preview
Things could not be going much better for Imanol Alguacil's Real Sociedad at the moment, sitting pretty at the top of their Europa League group while they build up a head of steam in their push for the top four in LaLiga.
As Sevilla languish in the early-season relegation zone, an opportunity to take their usual place in the Champions League spots has opened up, with La Real aiming to return to Europe's premier competition for the first time in 10 years.
While both Athletic Bilbao and Real Betis dropped points on the weekend, Real Sociedad took points from direct competitors Villarreal, recording a third-straight home victory to propel them to sixth, outside of the top four only on goal difference.
Having ground out a record eight 1-0 home wins last campaign, Sunday's win over the Yellow Submarine was their first of the new season, as Brais Mendez scored for the fourth league game in succession, to take his tally up to six for his new club.
Defeating Thursday's opponents rather comfortably in Moldova last week, as goals from David Silva and Aritz Elustondo secured a 2-0 win for the Txuri-Urdin, the Basque side should be relatively confident that they can extend their longest winning run in over two years.
For the visitors, only a win will do if Sheriff are to qualify for the round of 16 playoffs, assuming that Manchester United beat Omonia Nicosia at Old Trafford.
The Moldovan league leaders recorded an emphatic 3-0 victory over their Cypriot opponents in the opening group game, but have since struggled against the superior quality of Real Sociedad and Manchester United, falling to consecutive 2-0 defeats at the Sheriff Stadium.
Domestically, Stjepan Tomas's men continued their dominant unbeaten run in the league, making it 21 games without defeat and five without conceding in their 1-0 win at Dinamo-Auto on Sunday.
They face a much tougher trip on Thursday, though, and will be huge underdogs once again as they look for an unlikely win in San Sebastian.
Real Sociedad Europa League form:
W
W
W
Real Sociedad form (all competitions):
L
W
W
W
W
W
Sheriff Tiraspol Europa League form:
D
W
W
L
L
Sheriff Tiraspol form (all competitions):
L
D
W
W
L
L
Team News
Long-term absentees Umar Sadiq and Mikel Oyarzabal will once again be unavailable for Real Sociedad, despite the latter resuming training this week after rupturing his anterior cruciate ligament back in March.
Robin Le Normand made a late substitution appearance against Villarreal after a three games out with a foot injury, while fellow centre-back Igor Zubeldia made the bench for the first time in a month. Both are in contention for much-needed minutes here.
Norwegian striker Alexander Sorloth was wasteful on the weekend, and could be replaced by a returning Mohamed-Ali Cho, as Alguacil looks to rotate his squad to keep everyone fit and healthy as a jam-packed October continues.
Sheriff, on the other hand, are free of injuries heading into this important tie, but will be without important midfielder Moussa Kyabou after his red card against La Real last Thursday.
Live-wire striker Iyayi Atiemwen is also suspended, having picked up three yellow cards in three group-stage games so far, and should be replaced by Felipe Vizeu up front, while Abou Ouattara should return to the Europa League squad after scoring the winning goal on Sunday.
Real Sociedad possible starting lineup:
Remiro; Rico, Elustondo, Le Normand, Sola; Illarramendi, Guevara; Kubo, Silva, Cho; Fernandez
Sheriff Tiraspol possible starting lineup:
Koval; Kpozo, Kiki, Radeljic, Zouhouri; Akanbi, Badolo, Diop, Pernambuco; Vizeu, Ouattara
We say: Real Sociedad 2-0 Sheriff Tiraspol
Despite the best efforts of the Moldovan side, Real Sociedad were too strong in this contest last Thursday, and have home advantage this time around.
Expect the Spaniards to make it six wins in a row with another routine victory here.