Faksa has been ruled out for Monday's game against the Red Wings after he suffered a setback with his lower-body injury, Chris Pinkert of NHL.com reports.
Faksa returned to action Saturday against the Panthers after he missed five games due to his lower-body injury, but he'll be unable to suit up for the Blues' final game before the Christmas break. Whether he'll be available Friday against Nashville remains to be seen, but Mathieu Joseph will enter the lineup in his place Monday.