Unai Emery was coy on the state of Mesut Ozil's injury after the German was ruled out of Arsenal's win over Tottenham with a back spasm.
Ozil did not make the matchday squad on Super Sunday for the thrilling 4-2 victory, but Emery would not add to the club message before the game that a back problem had ruled him out.
Ozil was named on the bench in the 2-1 win over Bourmemouth last week, and did not warm up on the touchline once, with Emery insisting the physicality of the match was the reason for him being dropped.
In the post-match press conference on Sunday, when asked if Ozil could have played against Tottenham, Emery said: "He has back ache."
Then asked when he got the injury, Emery answered: "I don't know," and he answered the same when asked if Ozil was present at the match.
Ozil was brought off by Emery in the 3-2 defeat by Chelsea earlier in the season, and subsequently then left out of the win at West Ham in August.
Arsenal go to Old Trafford to face Manchester United on Wednesday night in the Premier League, sitting fourth in the table, eight points off leaders Manchester City.