LUANDA, January 18 – Ghana star Michael Essien injured his right knee training on Sunday and could miss a key Africa Cup of Nations clash against Burkina Faso here.A team spokesman said the Chelsea midfielder was taken to hospital for a scan and later rejoined his ‘Black Stars’ team-mates as they prepare for a must-win Group B fixture on Tuesday.

Ghana’s media officer Randy Abbey told AFP: "Michael suffered a right knee injury after a collision with a couple of teammates in the training session this morning.

"He was taken to a local hospital for a scan and we’ll get the results back tomorrow and then have a clearer idea of whether he can play."

Essien’s absence would be a huge blow to Ghana who face Burkina Faso at the 50,000-seat November 11 Stadium in the Angolan capital.

Ghana are one point behind Burkina Faso and the four-time champions need a win to avoid being eliminated after the first round of the biennial African football showpiece.

Essien arrived in Angola late for the tournament because snow delayed his flight from London and has been struggling to recover from a hamstring injury sustained playing for Chelsea in the Champions League last month.

He was kept on the bench until half-time against Ivory Coast last Friday in Cabinda by Serb coach Milovan Rajevac to avoid aggravating the injury and his second-half presence on the pitch could not prevent a 3-1 loss.