The Brazilian limped off during Saturday's win at Reading.
It came at the end of an impressive recent period for the former FC Porto star, who has brought added energy to Red Devils' ranks.
However, after a succession of major injuries, Anderson has now picked up another one that will keep him out for the remainder of the month.
"It is a hamstring," Ferguson told MUTV.
"It will be three or four weeks. It is not serious but it is a hamstring."
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