Ferreira, 30 has suffered a anterior cruciate knee ligament injury.
It's the same injury that has affected Michael Essien this season and Joe Cole.
Chelsea Ladies US star Lorrie Fair has also suffered two cruciates this season.
Essien is close to a return to first team action and could figure in tomorrow's FA Cup tie at Coventry. Cole is also out for the season, while Fair will return to the US after her visa expires.
It's a shame Fair was not offered the Ladies manager's job as she has done superb work for Chelsea as a player and ambassador.