The Frenchman was the Eagles summer selection to come in, following Oliver Glasner's exit on the back of winning the UEFA Conference League, but he's struggling in South London.
Just two wins from eight Premier League games, and one victory from three played in the Europa League, has put the club on red alert ahead of some crunch games before the November international break.
Veteran coach Sean Dyche has been flagged up as a possible option to come in, but talkSPORT have lined up three other candidates, who the club are rumoured to be looking at.
Contingency plans are being made at Selhurst Park with several key officials unconvinced over Sage's continuation and Thomas Frank and Vitor Pereira are on the shortlist.
Frank's stock in the Premier League - despite his struggles at Tottenham - with the Dane viewed as a solid operator at Brentford as was Pereira with Wolves.
Another candidate is former Premier League striker Robbie Keane with the Irishman keen to test himself at an English club for the first time as a manager.