Michy Batshuayi (25-year-old striker) spent the first half of the campaign on loan with the Spanish side, where he made 23 appearances and scored three goals, but now returns to the Premier League with the Eagles for the second half of the campaign.
Batshuayi moved to Chelsea from Marseille in the summer of 2016 and scored his first goal for the club in a Premier League away game at Watford.
He ended his first season at Stamford Bridge with nine goals, including the strike which secured the Premier League title as Batshuayi came off the bench to have a decisive impact away at West Bromwich Albion, scoring just seven minutes after his introduction.
Among the 10 goals Batshuayi scored during the first half of last season were a maiden Chelsea hat-trick, in a League Cup tie against Nottingham Forest, and a late winner in the Champions League against Atletico Madrid, before he spent the second part of the campaign on loan at Borussia Dortmund.
Batshuayi recovered from a knee injury in time to represent Belgium at the World Cup last summer, where he scored one goal, and in August the forward joined Spanish side Valencia on loan for the first half of this season.
Now he follows in the footsteps of Ruben Loftus-Cheek, who enjoyed a successful loan spell with Palace last season. Roy Hodgson’s side are currently 15th in the Premier League, four points clear of the relegation zone.