Manchester United will be without Anderson for several weeks after the midfielder pulled his hamstring in the 4-3 win over Reading.
The Brazilian scored United's first goal before limping off at the end of the first half in the seven-goal thriller at the Madejski Stadium.
Sir Alex Ferguson sympathised with Anderson, who had just forced his way into United's Premier League side.
After going three months without a league start, the 24-year-old had begun back-to-back games against West Ham and Reading but will now not feature again until 2013.
"It's a hamstring unfortunately. He'll be out for a few weeks," Ferguson told MUTV. "He's been playing really well and scored a great goal. I'm very disappointed for him."
Meanwhile, midfielder Michael Carrick said United's habit of mounting comebacks makes them believe they can always fight back after conceding.
The Premier League leaders trailed 1-0 and 3-2 to Reading but recovered to win. It was the seventh time they have won a league game from a losing position already this season
"That gives us the belief," he told MUTV. "Even if we do go a goal down we always feel we've got the firepower from different people; that's the strength in depth of the attacking options and that's what keeps driving us on and we never give up.
"Personally I always felt confident, even when we were going goals behind, that we could still get back in the game and win the game, and that obviously proved the case."