Micheal Essien (C) controls the ball during a training session on January 14, 2010 at the Chiazi stadium in Cabinda before their group stage match against Ivory Coast at the Africa Cup of Nations CAN 2010. ((Issouf Sanogo/AFP/Getty Images) )

Ghana midfielder Michael Essien was ruled out of the World Cup on Thursday after failing to recover from a knee injury.

The Chelsea player picked up the injury in January while at the Africa Cup of Nations in Angola.

"An evaluation by a combined team of medical experts from the Ghana Football Association and Chelsea Football Club revealed that Essien will not make full recovery until the end of July," the association said on its website.

Essien injured a hamstring while playing for Chelsea against APOEL Nicosia in the Champions League on Dec. 8.

He returned to play the second half for Ghana against Ivory Coast in the African Cup of Nations of Jan. 15, then injured his right knee two days later during training. He had hoped to return for Chelsea before the Premier League season ended, but had setbacks in his rehabilitation.

Ghana opens at the World Cup in Group D on June 13 against Serbia, then plays Australia on June 18 and Germany on June 23.

Essien helped Ghana reached the second round of the 2006 World Cup in its first appearance at the tournament.