Everton forward Theo Walcott has undergone abdominal surgery and will miss the resumption of the Premier League season.
Walcott suffered the problem in training as Everton prepare to face rivals Liverpool at Goodison Park on June 21.
He is expected to be out of action for four weeks after the procedure on Monday, so his season may not be over.
"The 31-year-old Everton forward had abdominal surgery on Monday evening, having developed symptoms following the first team's return to training," the club confirmed.
"He has now started his rehabilitation under the care of the club's medical team."
Walcott, who has made 21 Premier League appearances this season, posted on social media to thank fans for their messages of support.
Jean-Philippe Gbamin, Yerry Mina and Andre Gomes have also suffered injuries since the Toffees returned to training.
Earlier on Wednesday, Everton received approval to host the Liverpool match at their stadium behind closed doors, rather than being forced to play at a neutral venue.