The Red Devils held on to a 1-1 draw last week after a penalty from Mikel Oyarzabal canceled out Joshua Zirkzee's goal.
It leaves the last-16 tie in the balance heading into the second leg at Old Trafford tonight, with Ruben Amorim's side's season on the line.
A loss for Man United would end their chances of any silverware this campaign, so they will be giving their all to remain in Europe.
If they do progress, they will instantly find out who they're going to take on next...
Who could Man United face?
If Man United beat Real Sociedad, they will face Lyon or FCSB.
READ MORE ON FOOTBALL
Man United unveil stunning new images as 100,000-seat stadium to replace Old Trafford
Rice slammed for celebrating tackle against Man United's 'worst ever striker'
Lyon are currently 3-1 up on aggregate after the first leg of their tie against FCSB last week.
The French side were heading towards a draw until the final five minutes when striker Malick Fofana scored two in three minutes to claim a healthy lead.
The second leg of that tie will be taking place at the same time as Man United's second meeting with Real Sociedad on Thursday.
Should Amorim's side beat either Lyon or FCSB, then a potential semi-final against former manager Jose Mourinho could be on the cards.
Most read in Europa League
'I'm tired' - Mourinho pretends to fall asleep after press conference question
Jamie O'Hara doesn't notice Jason Cundy fall asleep during brutal rant about Tottenham
Lyon boss Paulo Fonseca breaks down in tears as players hug him after massive ban
McCoist rages as Rangers star forced off after sickening clash of heads with Butland
Mourinho's Fenerbahce or Rangers will be in the quarter-finals to face either Athletic Bilbao or Roma, with one of those four facing the Red Devils in the semis should they make it.
An all-Premier League final against Tottenham is possible, but Frankfurt and Lazio are sure to be contenders to go all the way.
talkSPORT BET: Latest Cheltenham Festival odds and free bet offers
Europa League last 16 in full
Left side
Tottenham vs AZ Alkmaar (0-1)
Frankfurt vs Ajax (2-1)
Olympiacos vs Bodo/Glimt (0-3)
Lazio vs Viktoria Plzen (2-1)
Right side
Rangers vs Fenerbahce (3-1)
Athletic Bilbao vs Roma (1-2)
Lyon vs FCSB (3-1)
Man United vs Real Sociedad (1-1)
talkSPORT Goals panel react to Bruno Fernandes' stunning free kick for Manchester United against Arsenal, but question the wall in the build up
Man United vs Real Sociedad: talkSPORT coverage
This Europa League last-16 second-leg tie will take place on Thursday, March 13.
Kick-off at Old Trafford is scheduled for 8pm.
talkSPORT will have live coverage of the game presented by Hugh Woozencroft.
Commentary will come from Jim Proudfoot and former Watford captain Troy Deeney.
To tune in to talkSPORT or talkSPORT 2 through the website, click HERE for the live stream.
You can also listen via the talkSPORT app, on DAB digital radio, through your smart speaker and on 1089 or 1053 AM.
Udinese 
Verona 
FC Augsburg 
VFL Wolfsburg 
Union Berlin 
Bayern Munich 
Werder Bremen 
Borussia Monchengladbach 
Everton 
West Ham 
Manchester City 
Brighton 
Mallorca 
Espanyol 
Lokomotiv Moscow 
Dinamo Moscow 
Avranches 
Bordeaux 
AC Milan 
Como 
RB Leipzig 
Borussia Dortmund 
Villarreal 
Real Madrid 
Angers 
Monaco 
Guingamp 
FC Porto 
Avs Futebol Sad 
Waalwijk 
PSV 
Girona 
Valencia 
Akron Togliatti 
CSKA Moscow 
Venezia 
Napoli 
Celtic 
Rangers 
Arsenal 
Chelsea 
Fulham 
Tottenham 
Twente 
Feyenoord 
Lyon 
LE Havre 
Bologna 
Lazio 
Reggiana 
Sampdoria 
VFL Bochum 
Eintracht Frankfurt 
Roma 
Cagliari 
Sevilla 
Athletic Bilbao 
Ajax 
AZ Alkmaar