Sir Alex Ferguson has confirmed that Anderson picked up an injury in last night's Champions League win over Otelul Galati.
The Brazilian midfielder was subbed off in the second half of the 2-0 victory and is now in doubt for the weekend's league meeting with Sunderland adding to Ferguson's midfield concerns which include Tom Cleverley, Darren Fletcher, Michael Carrick, Ashley Young and Ryan Giggs whilst versatile defender Chris Smalling is still out.
However, there is good news for United fans with centre-half Nemanja Vidic back after his European suspension.
"Vidic will be back but maybe Anderson is the one player who picked up an injury last night," said Fergie. "We'll see what he's like. He could be doubtful.
"There will be no returns for Young, Smalling or Cleverley though."