The injury-hit Sri Lankans have lost opener Pathum Nissanka (groin) for Sunday's match at Bellerive Oval, while Ireland are unchanged from their impressive nine-wicket win over two-time champions West Indies.
Sri Lanka were already without injured pace spearhead Dushmantha Chameera and top-order batter Danushka Gunathilaka after they were ruled out of the tournament during the group stages.
Ashen Bandara replaces Nissanka and will play his fifth T20 international.
Sri Lanka bounced back from a shock loss to Namibia to progress to the Super 12 stage. Ireland, meanwhile, finished second in Group B with two wins from three games.
"(The group stage) was high-pressure cricket. To come through that gives us immense confidence," Ireland skipper Andy Balbirnie said.
"The pressure over the next couple of weeks will be different. (We) want to push the top teams as hard as we can."
SRI LANKA: Dhananjaya de Silva, Kusal Mendis, Charith Asalanka, Ashen Bandara, Bhanuka Rajapaksa, Dasun Shanaka (capt), Wanindu Hasaranga, Chamika Karunaratne, Maheesh Theekshana, Lahiru Kumara, Binura Fernando.
IRELAND: Paul Stirling, Andy Balbirnie (capt), Lorcan Tucker, Harry Tector, Curtis Campher, George Dockrell, Gareth Delany, Mark Adair, Simi Singh, Barry McCarthy, Josh Little.
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