Chinese Super League champions Guangzhou Evergrande are facing the toughest challenge this season?as?key players?set to miss the crucial fixture against Thailand's Buriram United in AFC Champions League group stage.

Conca, who has scored four goals in five games during the campaign, was handed a nine-match suspension by the club following his reaction to being substituted in the second half of the 3-1 home defeat by Jeonbuk Hyundai Motors two weeks ago.

And coach Lee Jang-soo will also be without suspended number one goalkeeper Yang Jun, while Brazilian striker Muriqui is an doubt injury as Guangzhou seek a third win of the campaign to cap their tournament debut with a place in the last 16.

"He (Conca) will not be playing in tomorrow's game because of his earlier ban. I cannot reveal the starting line-up for tomorrow's game just yet," said Lee Jang-soo, who arrived with his squad in Thailand last Tuesday.

"He (Muriqui) is undergoing treatment and has been practicing with his team. We'll see how ready he is after today's practice and will see if he is fit to play tomorrow."

Conca, Muriqui and Cleo combined for 11 goals in AFC champions league for the Guangzhou side, which hasn't experienced a single match without any two of them before.

Fortunately, they have a healthy Cleo, who scored the equalizer in their home match against Burriram.

"We know it is a vital match, and without Conca and Muriqui, it will be tougher. So I must take the responsibility," said the 26-year old forward.

Guangzhou's defeat by Jeonbuk saw the CSL side concede top spot in Group H to the K-League side, with Lee Jang-soo's side two points off the pace alongside Japan's Kashiwa Reysol heading into the final round of fixtures.

Fellow tournament debutants Buriram are still just a point adrift at the foot of the table despite suffering back-to-back defeats by Jeonbuk before losing to Kashiwa last time out, and can qualify with victory as long as the J.League side fails to win in Korea against Jeonbuk.

“This is a very important match. Although we are missing one key defensive player, we are determined to collect this much needed win for the team,” coach Attaphol Puspakom said.