The 26-year-old Windies vice-captain sustained a chipped bone in his right thumb after being struck by Barbados pacer Fidel Edwards on the opening day of the final round Carib Beer Series match between Guyana and Barbados at Bourda on Monday.
''I am very disappointed. I was looking forward to the final four (of the KFC Cup) and preparing for the World Cup,'' Sarwan was quoted as saying by Windies Board website.
He said he hoped the injury healed quickly in time for the World Cup, starting March 13 at home.
Sarwan had made 18 in the Guyana innings when he failed to negotiate a rising delivery from Edwards and was struck on the glove.
He received treatment on the field from Barbados' physiotherapist and was later taken to hospital for a precautionary X-ray where the extent of the injury was revealed.
It is the second injury setback for Sarwan in recent times. He was forced out of the tour of Pakistan late last year when he fractured a bone in his foot after being struck by an Umar Gul delivery.
The injury forced Sarwan to miss West Indies' four-match ODI series tour to India last month.