The right-back came off at half-time during United's 4-1 win over Aston Villa on Saturday with a thigh strain and he did not feature in the 15-minute training session open to media at Carrington on Monday.
The good news for United was that centre-backs Rio Ferdinand (back), Chris Smalling (hamstring) and long-term absentee Jonny Evans (calf), who all missed Saturday's victory, took part in the session at the Aon Training Centre.
Left-back Alex Buttner ended the Villa game with a tight hamstring, but he trained, as did winger Antonio Valencia, who missed Saturday's game with a knee injury.
The only other absentees from the session were injured striker Robin van Persie, the suspended Patrice Evra and midfielder Tom Cleverley.
United are big underdogs to progress to the last four of the competition at the expense of the reigning European champions, who won the Bundesliga last week with seven games to spare.
The Germans will come to Manchester without midfielder Thiago Alcantara though as he suffered a knee injury during Bayern's 3-3 draw with Hoffenheim on Saturday.