Last meeting: United's only clash with Sociedad to date came just under a fortnight ago, when the Reds secured an important 1-0 home win.
Did you know? Inigo Martinez's own goal at Old Trafford was, at just 69 seconds into the match, the fastest goal in the Champions League this season.
The manager: Jagoba Arrasate has been in charge of Real Sociedad - his first managerial post - since June 2012. A native to the Basque region, he led La Real to an impressive fourth-place finish in La Liga, securing Champions League qualification.
Star man: United will have to keep a watchful eye on former Arsenal man Carlos Vela. The Mexican striker, who first moved to Sociedad on loan in 2011, scored an impressive 61 goals in his first two seasons in Spain and appears to have continued in a similar vein this term with 13 strikes so far.
Quote/unquote: "It will be a difficult test against (Real) Sociedad. To go and play against any side in Spain who have qualified will be a hard test, but we will go over there and try and get a good result that will continue our good form in the group." David Moyes.
Whistle-blower: Italian referee Nicola Rizzoli will be taking charge of the match on Tuesday. Rizzoli, who officiated last season's Champions League final between Bayern Munich and Borussia Dortmund, is perhaps more familiar to United fans for sending off Rafael in the 2010 Champions Leage quarter final match against Bayern at Old Trafford.