Asalanka was still chosen in the 25-man preliminary squad for the global tournament but his demotion as skipper in the shortest format had been touted for a while.
"We decided that Dasun Shanaka should be captain until the end of the World Cup, after talking to head coach Sanath Jayasuriya as well," Wickramasinghe said.
"The previous committee had chosen a list of 25 players. We spoke to Jerome Jayaratne, the head of the high performance, as well as Sanath Jayasuriya.
"We decided to announce that same 25 as a preliminary squad for the World Cup. We are looking at Dasun as an allrounder.
"We'll have to talk to Sanath Jayasuriya and work out what is required of him."
Asalanka missed the T20 tri-series in Pakistan due to illness with Shanaka staning in as captain for the tournament where Sri Lanka lost the final.
The preliminary squad includes the return of Niroshan Dickwella, who last reprsented Sri Lanka back in March 2023.
Sri Lanka preliminary T20 World Cup squad: Dasun Shanaka (Captain), Pathum Nissanka, Kusal Mendis, Kamil Mishara, Kusal Perera, Dhananjaya de Silva, Niroshan Dickwella, Janith Liyanage, Charith Asalanka, Kamindu Mendis, Pavan Rathnayake, Sahan Arachchige, Wanindu Hasaranga, Dunith Wellalage, Milan Rathnayake, Nuwan Thushara, Eshan Malinga, Dushmantha Chameera, Pramod Madushan, Matheesha Pathirana, Dilshan Madushanka, Maheesh Theekshana, Dushan Hemantha, Vijayakanth Viyaskanth and Traveen Mathew.
Fatima Sana and Chamari Athapaththu both looked to the future after a frustrating day in Colombo saw Pakistan and Sri Lanka end their ICC Women's World Cup campaigns with a washout.
The Proteas Women made it four consecutive wins at the ICC Women's World Cup after a commanding 10-wicket victory against co-hosts Sri Lanka in what was a rain-reduced encounter in Colombo.
Nat Sciver-Brunt scored a century and Sophie Ecclestone took wickets as England made it three wins from three at the ICC Women's World Cup after beating co-hosts Sri Lanka by 89 runs in Colombo.
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