Manchester United boss Sir Alex Ferguson explained his surprise first-half substitutions during victory at Reading.

Brazilian duo Rafael and Anderson were substituted in the first half and although Ferguson explained Rafael's departure was tactical he confirmed goalscorer Anderson faces a spell on the sidelines.

"Rafael had been booked, I don't think there was any danger in him being sent off because it was an innocuous challenge but we really needed to get height into the team," he said.

"(Anderson's) is a hamstring unfortunately and he will be out for a few weeks, he had been playing well the lad, scored a great goal and it is disappointing."