The visitors reached the final of last season's competition, before just falling short against Manchester City, while their hosts enter Europe's premier tournament for the first time in 10 years.
After 10 years away from Europe's top competition, Real Sociedad earned a place in the Champions League group stage this season thanks to their fourth-placed finish in La Liga last time around, as Imanol Alguacil's side amassed 71 points from their 38 outings.
That was alongside their Europa League campaign, in which La Real topped their group with 15 points and earned automatic progression to the round of 16, netting 10 goals and only conceding twice as they managed five victories among a single defeat to Manchester United.
That saw Alguacil's men earn automatic progression to the knockout stage and meet Roma in the round of 16, but they fell short against the eventual runners-up, losing 2-0 away in the Italian capital following goals from Stephan El Shaarawy and Marash Kumbulla, before seeing their home leg end goalless and dropping out as a result.
Then on the back of their pleasing league finish, the Basque outfit have not yet managed to pick up where they left off in the new term, having managed just six points from their five La Liga outings thus far, starting with three straight draws before scoring a first three-point haul in an eventful 5-3 win over Granada, thanks to a Takefusa Kubo brace, goals from Martin Zubimendi and Ander Barrenetxea and a Miki Bosch own goal.
Now following on from a 2-1 defeat away at leaders Real Madrid at the weekend, in which they went ahead in the first half through Barrenetxea only for Los Blancos to turn the game around with goals from Federico Valverde and Joselu, Alguacil's side will look to bounce back and kick off with a home victory on their return to Champions League action on Wednesday.
They meet an Inter Milan side who head into the new Champions League campaign having fallen at the final hurdle in their bid to win the continental title for the fourth time and their first since 2010 last season.
Simone Inzaghi's side finished second in their group behind Bayern Munich, amassing 10 points and pipping giants Barcelona to the round-of-16 place, before progressing past Portuguese outfits Porto and Benfica with 1-0 and 5-3 aggregate victories.
That set up a semi-final tie with rivals AC Milan, and after a 2-0 victory in the first leg at the San Siro thanks to early goals from Edin Dzeko and Henrik Mkhitaryan, they wrapped up the aggregate triumph with a 1-0 victory a week later, booking a meeting with Manchester City in the final, in which they eventually fell just short, losing 1-0 to the English champions as Rodri netted the only goal of the game 22 minutes from time.
On the back of that disappointment, after an admirable run through the competition, and their third-placed finish in Serie A, I Nerazzurri head into their Champions League curtain-raiser on the back of a perfect start to the new Italian campaign, having won their opening four outings by scoring 13 goals and only conceding once, most recently thrashing AC Milan 5-1 in the Derby della Madonnina as Mkhitaryan netted a brace alongside goals from Marcus Thuram, Hakan Calhanoglu and Davide Frattesi.
With momentum on their side from that start and the weekend's beating of their rivals, Inzaghi's men will travel to the Basque Country with the aim of starting with three points in their bid to again go deep into Europe's top competition.
Real Sociedad are unable to call on attacker Carlos Fernandez, who will serve a continental suspension after being sent off in last season's Europa League defeat to Roma, while summer signing Andre Silva is sidelined by injury alongside Martin Merquelanz.
In a 4-3-3 shape, the line will be led by Mikel Oyarzabal in Silva's absence, with the Spaniard likely being flanked by Takefusa Kubo and Ander Barrenetxea, both of whom have impressed with three goals apiece so far this season.
Elsewhere, Martin Zubimendi is a key man in midfield and will likely be joined by Brais Mendez and Mikel Merino, while Robin Le Normand and Igor Zubeldia will continue their centre-back partnership with Arsenal loanee Kieran Tierney bound to start on the left-hand side of the back four.
Inter Milan come into Wednesday's trip with a clean bill of health, and Inzaghi may look to deploy an unchanged starting XI from their thrashing of AC Milan at the weekend, although the likes of Marko Arnautovic and fifth goalscorer Davide Frattesi are fighting to come in from the start, as is defender Stefan de Vrij.
He should be handed a start after Matteo Darmian, Francesco Acerbi and Alessandro Bastoni were preferred last time out, with summer signing Benjamin Pavard also hoping to feature from the outset, while Henrik Mkhitaryan should again operate in an advanced midfield role after his brace last time out, likely alongside Hakan Calhanoglu and Nicolo Barella.
At the top end of the pitch, the line will again be led by star man Lautaro Martinez, who has already notched up five Serie A goals this season after hitting 28 in all competitions last term, including three alongside three assists in their Champions League campaign.
Real Sociedad possible starting lineup:
Remiro; Traore, Le Normand, Zubeldia, Tierney; Mendez, Zubimendi, Merino; Kubo, Oyarzabal, Barrenetxea
Inter Milan possible starting lineup:
Sommer; Pavard, De Vrij, Bastoni; Dumfries, Barella, Calhanoglu, Mkhitaryan, Dimarco; Martinez, Thuram
We say: Real Sociedad 1-2 Inter Milan
Wednesday's game should certainly be close and intriguing, and Real Sociedad will be keen to mark their return to the Champions League with a positive home result, but the visitors do possess more quality and experience on the continental stage and we fancy them to take all three points in the opener.
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