A-League champions Central Coast Mariners will be without star playmaker Marcos Flores for the rest of the A-League season after scans confirmed he has a ruptured ACL.

The Argentine is expected to undergo reconstruction surgery on his right knee for the injury suffered in training on Thursday.

The diagnosis means the Mariners are certain to search for a quality replacement in the January transfer window.

It comes at an especially bad time as fellow Mariners playmaker Michael McGlinchey is due to play his last game for the club on Sunday before heading off to join former Mariners coach Graham Arnold at his Japanese club Vegalta Sendai.

Mariners coach Phil Moss vowed the team would maintain a stern title defence despite the latest blow.

“It is a bitter blow for Marcos and for the club,” said Moss.

“Over the coming months we will do whatever we can to help Marcos in his recovery and return to the game.

“Despite the loss of Marcos for this season we will continue to show that we are made of tough stuff here at the Mariners.

“We have the quality and the mental strength to continue moving in the right direction.”

Flores, 28, said he had full faith his teammates could cover his absence.

“My wish for the team is to keep focused. We are in the fight to keep the trophy on the Coast and I believe in my teammates,” Flores said.

“I trust in the medical team and trust that the Mariners as a family will look after me. Today I am in a little bit of pain, but I feel the support from everyone and I thank the fans for their support because they have been very kind to me.”