Michael Essien is expected to be back in action in six months after a successful surgery on his right knee, his club, Chelsea FC confirmed today.The Ghana international Monday underwent surgery on his right knee to repair a ruptured anterior cruciate ligament and meniscus.Essien suffered the injury last week in training with Chelsea.The Ghana Football Association has in a message of sympathy extended to him wished him "a full and speedy recovery".Source: GFA.org