London - Everton's stuttering Premier League campaign suffered a blow on Monday as they revealed exciting wing Yannick Bolasie is to undergo surgery on a serious knee injury.
The 27-year-old Democratic Republic of Congo international - whom Everton signed for 25 million ($32m, €29.5m) from rivals Crystal Palace in the close season - limped off in the 68th minute of the 1-1 draw with Manchester United on Sunday.
Everton had their worst fears confirmed on Monday.
"Yannick Bolasie to undergo knee surgery after scans confirmed a serious ligament injury against @ManUtd. Come back stronger, Yannick," tweeted Everton, without saying how long he might be out of action for.
Bolasie has been an ever present in the starting line-up this season for Everton, who have gone four games without a win in the Premier League after a promising start under manager Ronald Koeman.