Palace slumped to a heaviest loss in 70 years against their bitter rivals on Sunday, conceding three goals inside the opening 10 minutes at the Amex Stadium.
The Eagles have now won just two of their first seven Premier League games under Sage, and Standard Sport understands there is a growing belief within the Palace dressing room that the Frenchman could be relieved of his duties.
After a summer of change at Palace, though, Sage has struggled to get his ideas across, and their defensive collapse against Brighton means they have now shipped more goals than any other Premier League team this season.
Sage is facing a serious challenge to convince Palace’s decision-makers that he should remain at the helm, and Standard Sport understands that several players are disillusioned with his methods and lack of communication.
As early as the start of September, concerns were raised that Sage was struggling to implement his style of play and his decision to drop centre-back Jaydee Canvot after Palace’s 3-2 home defeat by Ipswich drew criticism.
However, after a 0-0 draw with Leeds, Sage was afforded more time to get his methods through to his players and improve the team’s defensive issues.
Palace, though, have continued to look vulnerable at the back, conceding eight goals in their last two games against Brighton and Lyon.
Standard Sport understands that Sage’s future is under serious scrutiny as Palace prepare to take on Besiktas and Newcastle this week, with the club already sounding out potential replacements.
Positive results against Besiktas and Newcastle would ease the pressure on Sage, but as it stands, he heads into a critical week with his job on the line.