Manchester United boss Ole Gunnar Solskjaer says teenage pair Shola Shoretire and Amad must wait for their full debuts.
Amad, 18, and Shoretire, 17, made their debuts in the wins over La Real and Newcastle United last week but will have to wait for their first competitive starts.
United are 4-0 up on aggregate against Sociedad and all but through to the last 16 of the Europa League, with the Spanish side due at Old Trafford three days before United travel to Chelsea in the Premier League.
MSolskjaer is expected to rotate but is not planning to name either of the teenage debutants in his starting XI.
When asked if Amad or Shoretire could start, Solskjaer replied: "Probably not, Shola and Amad, no. I'm not sure that would be fair on them, they'll be in the squad."