Casey to miss World Match Play
Paul Casey is out of the Volvo World Match Play Championship in Spain starting on Thursday and will be replaced by Swede Robert Karlsson.
Casey suffered a recurrence of shoulder trouble - he dislocated it snowboarding on Christmas Eve - at the Players Championship and withdrew on the 10th hole.
He hoped at first he would recover in time for the 24-man event at Finca Cortesin near Marbella, but having already missed the first two months of the season he faces another lay-off.
"Unfortunately, despite having had intensive treatment since last Thursday, I have been advised not to play in the Volvo World Match Play Championship," he said in a statement.
"I am absolutely gutted as it is one of my favourite events and I was really looking forward to a week of match play to kick-start my season.
"I am very sorry to miss out, especially as Volvo were kind enough to give me an invite."
Casey will have more treatment before making a decision on next week's BMW PGA Championship at Wentworth. He won that three years ago.
Karlsson said: "I am absolutely thrilled to receive this invitation.
"I have only qualified once before, so this is a great opportunity for me, especially in a Ryder Cup year, and I am really excited about the week ahead."
Casey's exit leaves the former world number three, now outside the top 50, with a mountain to climb to make it back into the Ryder Cup team.
He was ranked ninth in the world two years ago when then European captain Colin Montgomerie chose not to give him a wild card, preferring Padraig Harrington, Luke Donald and Edoardo Molinari instead.
After his withdrawal on Thursday he said: "My shoulder felt tired and tender when I made my way to the first tee.
"I decided to give it a go as I thought I could play through it, but during the round it flared up, which is when I decided to withdraw.
"I am very disappointed. My game has been coming around and I felt confident, but my body told me otherwise.
"My recent schedule has been extremely busy and the lack of rest has taken its toll. It's a long season and my health is the number one priority.
"I am going to re-evaluate and see where I am after I get some treatment. I will continue to strengthen where I need to and then go from there."