The former Adelaide United and Melbourne Victory star will be assessed on Friday to reveal the extent of the damage with the club releasing a statement confirming the injury.
"Central Coast Mariners wish to notify its members, fans and media that Argentine playmaker Marcos Flores today sustained an injury to his right knee at training," the statement said.
"Flores will have scans on the injury on Friday which will determine the extent of the injury.
"Central Coast Mariners will update members, fans and media regarding Flores’ condition once the scans have been fully analysed by the club’s medical department."
The 28-year-old, who moved to Gosford from the Victory over the off-season, has been showing signs of returning to the kind of form that made him such a feared player at Adelaide after finding life at AAMI Park difficult.
Flores has been a central figure for Phil Moss' team this season, making 12 appearances and scoring three goals in the A-League.
Whatever the result of the scans it now appears unlikely the Argentine will be available for the Central Coast's game against Melbourne Heart on Sunday with the club hoping he won't be facing an extensive injury lay-off.
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