Scans after Thursday’s Champions Trophy semi-final against India showed Dilshan had suffered a calf muscle tear and will be in recovery for up to six weeks.
Tharanga has been out of the national team since earlier this year but played first class cricket where he averaged more than 60 in 14 innings.
Also missing from the touring Sri Lanka team is Thisara Perera who has been replaced by spinner Ajantha mendis. Sri Lanka play the West Indies in the opening match at Sabina Park on June 28, and India on July 2 at the same venue before the series shifts to Trinidad.
Mumbai Roundup: 9 incidents that took place this week
Photos: Ajay Devgn, Parineeti, Tabu at 'Golmaal Again' trailer launch
Photos: Dipika Pallikal Karthik oozes oomph in bikinis and sarees
Photos: Kareena Kapoor Khan's grand birthday bash
Photos: 'Dangal' girls Sanya Malhotra, Fatima Sana Shaikh's dinner outing