Kusal Janith Perera will leave for Australia to be on standby for Dimuth, Sri Lanka Cricket says in a press release.
Dimuth is the fourth Sri Lankan player to receive injuries during the ongoing World Cup.
Earlier, Dhammika Prasad, Jeewan Mendis and Rangana Herath succumbed to injuries and were replaced by Dushmantha Chameera, Upul Tharanga and Seekuge Prasanna.