Rafa Benitez has emerged as a shock contender for the Everton job.
Mirror Football understands that Blues owner Farhad Moshiri is seriously considering the former Liverpool boss as a successor to Carlo Ancelotti, despite the potential for widespread dissent and anger from the fans.
Benitez once called the Blues a "small club", but has backtracked on those comments by apologising to Everton supporters in recent days, as he confirmed he would be interested in the vacant position.
And that has sparked an interest from majority shareholder Moshiri, who has hit a roadblock in his search for a new manager, with top two candidates David Moyes and Nuno Espirito Santo both proving elusive targets.
Former Wolves boss Santo priced himself out of the Palace job with some extreme demands which included bringing six members of staff with him, and his agent Jorge Mendes looking after transfer business.
Those same demands are now causing strong second thoughts with Moshiri, and with the Goodison club also reluctant to upset West Ham - with whom they have a close relationship - the club have extended their short list.
Director of Football Marcel Brands will spend the next few days making contact with further candidates, with Benitez strongly pushed by Moshiri.
Talks are likely to take place with the former Reds boss this week, even though there are concerns from within the club that Benitez could not win the fans over after his comments.
The Spanish coach is a divisive figure, who fell out with his owners at Liverpool, Newcastle, and even Valencia where he made his name. But Moshiri is impressed by his track record.
Former Everton boss Roberto Martinez has also emerged as a candidate on the short-list compiled by Brands, after taking Belgium to number one in the world rankings. His tenure at Goodison ended badly, but like Benitez he would be interested in a return to Merseyside.
He could become a live candidate if Belgium progress at the European Championships which start this weekend, and there is backing for the Spanish coach from the Director of Football.
Christophe Galtier is another who is likely to be approached by Brands in the coming days, with the Frenchman, who led Lille to an historic title win this season in Ligue 1, now on the short-list.
Galtier beat PSG to the French title, but then resigned just days later, claiming he had a deep belief his time was up at the club, with Nice expressing a strong interest in his services.
Brighton boss Graham Potter also has some backing within the Everton boardroom, but he would be an outside contender.
Moyes remains a favourite with Moshiri, but the Blues would not make an approach unless they were given permission to speak to him by West Ham.