Cenk Tosun will undergo surgery next week after suffering an ACL injury during training with Crystal Palace, Everton have confirmed.
The Turkish striker, who was Palace's only January arrival, returned to the Everton training ground on Thursday for further assessment and will miss the rest of the season and likely the Euros this summer.
Tosun scored one goal across five appearances for Crystal Palace and could have seen his deal made permanent in the summer for a fee of £20million.
The 28-year-old will have his rehabilitation undertaken by parent club Everton.
A statement from Everton read: “Cenk Tosun has returned to Everton and will undergo surgery next week after sustaining an injury to his anterior cruciate ligament (ACL) during training with loan club Crystal Palace.
"Striker Tosun, who has scored 10 goals in 51 Everton appearances following a transfer from Besiktas in January 2018, completed a temporary move to Selhurst Park two months ago.
"The Turkey international, capped 42 times by his country, struck on his first Palace start in a 2-2 draw at Premier League champions Manchester City on 18 January.
"Tosun, 28, played five times for Roy Hodgson’s team but his time in south London has been cut short after he was hurt in a training session on Monday.
"The player will continue his rehabilitation under the care of Everton’s medical staff at the Club’s USM Finch Farm training headquarters following the surgical procedure on his ACL."
Following the arrival of Tosun in the January window, Palace allowed striker Connor Wickham to join Championship side Sheffield Wednesday on loan for the rest of the season. The Eagles do not have the option to recall Wickham from Hillsborough.