Anderson will be out of action until February after Manchester United boss Sir Alex Ferguson confirmed the Brazilian international’s damaged cruciate knee ligament was worse than they originally feared.
Anderson, who two years ago was forced to undergo an operation following cruciate ligament damage, was sent back to the same specialist in Portugal for further assessment and is expected to miss the entire Christmas fixture list, with Ferguson describing the prognosis as “not good news”.
"Anderson is out until February with a knee injury," Ferguson said.
"He's been sent to Portugal to see a specialist who operated on him before. Not good news."
Anderson joins midfield team-mate Tom Cleverly as long-term injury concerns for Ferguson, however the Scot insists he won’t be tempted into the transfer marker in January for cover.
"It is easy to say you are going to buy players but it is not easy to buy them for Manchester United, especially in January," he said.
"I do not see anyone who could make us a better team.
"There are two or three players but they are not available, so there is no point even going there."
Anderson hasn’t played for United since their UEFA Champions League tie against Otelul Galati in November.