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