Niasse joined Everton from Russian side Lokomotiv Moscow for £13.5m in the summer of 2016 but failed to establish himself at Goodison Park under Roberto Martinez or Ronald Koeman, who swiftly froze the Senegalese star out of the first-team picture on Merseyside.
Niasse had to spend the first half of last season plying his trade for Everton's Under-23 side and scored seven goals in five games for David Unsworth's side as they achieved Premier League 2 glory.
He did eventually get a sustained crack at the Premier League during the second half of the campaign when Hull City agreed to take him on loan until the end of the season. The Senegalese star managed to give a good account of himself on Humberside, though he could not fire the Tigers to Premier League safety.
Newly-promoted outfit Brighton and Hove Albion and Watford were both credited with interest in Niasse, but the Daily Mail claim that Palace have agreed a deal with Everton, who are also scouring the market for a striker.
The former Brann forward has only managed to score five goals in 26 Premier League appearances for both Everton and Hull respectively, but Palace manager Frank de Boer is hoping the 27-year-old will be able to complement main forward Christian Benteke and create space for the Belgium international, who was linked with a move to Everton earlier this summer.
The signing of Niasse would be Palace's second permanent acquisition of the transfer window, but the Senegal international may not be the only forward to arrive at Selhurst Park before the 11pm deadline.
Besiktas forward Cenk Tosun is also on De Boer's radar and is close to completing a move away from the Turkish giants, who signed former Manchester City and Middlesbrough striker Alvaro Negredo earlier this summer.
Palace's search for a striker seems to be coming to an end, but Everton are still looking to replace Romelu Lukaku, who joined Manchester United almost two months ago. Lucas Perez, Michy Batshuayi and Raul Jimenez have all been linked with moves to the blue half of Merseyside , which has already seen 20 players either arrive or leave Everton this summer.