Somerset batsman Nick Compton has been ruled out of Saturday's Friends Life t20 finals day in Cardiff.
The 29-year-old batsman, who has been a key figure in the side this year, is suffering from a prolapsed disc and may not play again this season.
Somerset face Hampshire in the second semi-final in Cardiff on Saturday, where they will be looking to go one better than their three consecutive runners-up finishes.
The club's director of cricket Brian Rose said: "Unfortunately Nick will not be able to play on Saturday and things are not looking good for him at the moment.
"He is going to have another injection to ease the pain but at the moment we have to face the possibility that he will not play again this season."
Pace bowler Alfonso Thomas (hamstring) and leg-spinner Max Waller (intercostal muscle) have been fighting for fitness too but there was more positive news on their recoveries.
"Both have been able to bowl in the nets this week and as things stand they have a decent chance of being fit for finals day," said Rose.
Ireland's one-day specialist Kevin O'Brien, who hit a match-winning century to defeat England at last year's World Cup, will also be linking up with Somerset for the day.