Stevan Jovetic will be out of action for the rest of the season after injuring his anterior cruciate ligament in a 0-0 draw with Reims.
The principality club also saw Fàbregas go off injured with an apparent calf problem inside 14 minutes, with Jean-Eudes Aholou taking his place.
Both sides hit the woodwork in the match. The 0-0 draw means Monaco is still seven points clear of the relegation zone with several matches to go.
The team has not yet lost a match since manager Jardim returned to the club to take over the reigns from the embattled Thierry Henry.