Charith Asalanka's tenure as skipper of the Sri Lanka team was thrown into uncertainty after the southpaw came back home from Pakistan in the middle of the triangular series there.
The replacement players will be available for Mumbai Indians only if they qualify for the play-offs.
Jos Buttler's unbeaten half-century led England to an emphatic eight-wicket victory over Sri Lanka, completing a 3-0 T20 series whitewash and elevating England to the top of the T20 world rankings.
De Silva and veteran Angelo Mathews were not included in the 16-man T20 squad but there was a place for Hasaranga.
Sri Lanka captain Charith Asalanka led by example and smashed a belligerent hundred to set up a 49-run victory over a depleted Australia.
All-rounder Dasun Shanaka will lead a strong Sri Lankan side for the T20 World Cup, featuring key players including Pathum Nissanka, Kusal Mendis, Kusal Perera and Charith Asalanka.
Two senior players of the Sri Lankan cricket team, including skipper CharithAsalanka, currently touring Pakistan for a T20 tri-series will be returning home due to illness, Sri Lanka Cricket (SLC) said on Monday.
'I am really pleased with the performance. Almost a perfect game for us. The pacers did the job (but) only the last over went wrong for us.'
Images from the ICC World Cup match between Sri Lanka and Bangladesh, at the Arun Jaitley Stadium, in New Delhi, on Monday.
The International Cricket Council has confirmed pacer Pramod Madushan as the replacement for Sri Lanka quick Eshan Malinga, who was ruled out of the Twenty20 World Cup on home soil after dislocating his shoulder against England last week.
Pathum Nissanka scored his seventh one-day international century with 122 from 136 balls as Sri Lanka defeated hosts Zimbabwe by five wickets to clinch the two-game series at the Harare Sports Club on Sunday.
Sri Lanka didn't have the best of preparations for the T20 showpiece as they were whitewashed 0-3 by England in a home T20 series. Ireland will be led by veteran Paul Stirling and feature key players like Harry Tector and Josh Little.
Afghanistan will need to play with more flair and freedom in their must-win Asia Cup group match against Sri Lanka in Abu Dhabi on Thursday.
Charith Asalanka's heroic innings secured Sri Lanka's place in the Asia Cup 2023 final,
Contrasting centuries from Joe Root and Harry Brook powered England to a 53-run victory over Sri Lanka in Colombo on Tuesday to secure a 2-1 victory in the three-match ODI series.
'Talat has done very well in domestic cricket. I know him for several years. He has been working really hard with his game, so I'm really happy for him.'
The islanders, led by Charith Asalanka, have quietly built a formidable unit combining top-order solidity with middle-order power and a spin attack tailor-made for UAE conditions.
'I think they are the best players of spin in the Sri Lanka squad. And Charith, he showed great character. Special feeling, back to back finals.'
Joe Root's all-round performance has helped England defeat Sri Lanka by five wickets in the second ODI at the R. Premadasa Stadium on Saturday.
India and Bangladesh have two points each with Suryakumar Yadav's men leading the standings owing to a superior net run rate. Sri Lanka and Pakistan occupy the third and fourth spots respectively.
In all the three group matches, Sri Lanka thrived while chasing and one would expect the Islanders to continue the same trend if they win the toss on Saturday.
This is not the way we wanted to play, we have to do better than this: Asalanka
Along with Hasaranga, Sri Lanka have Dunith Wellalage and Maheesh Theekshana among spin bowling options.
Sri Lanka must improve their batting against slower bowlers when they face New Zealand in a crucial T20 World Cup Super Eight clash in Colombo, with both teams chasing their first win.
'We had a great chance to chase 150 odd in the last game. But that's the nature of T20 cricket.'
Sri Lanka skipper Charith Asalanka felt the first two overs bowled by pacers Nuwan Thushara and Dushmantha Chameera set the platform for their commanding Asia Cup victory over Bangladesh in Abu Dhabi on Saturday.
Bangladesh pulled off a thrilling four-wicket win against Sri Lanka, chasing 169 with just one ball to spare in Dubai on Saturday.
Mitchell Santner's all-round showing helped New Zealand recover from a poor start to crush Sri Lanka by 61 runs in the T20 World Cup Super 8s,
Opener Pathum Nissanka struck 68 as Sri Lanka beat Hong Kong by four wickets in their Asia Cup match in Dubai on Monday.
This is Sri Lanka's biggest victory over Australia in ODIs in terms of runs.
Afghanistan skipper Rashid Khan on Tuesday didn't mince words while criticising the "not so ideal" scheduling
Images from the T20 World Cup match between Bangladesh and Sri Lanka, in Sharjah, on Sunday.
New Zealand reached the Twenty20 World Cup semi-finals after Pakistan crashed out despite a victory against Sri Lanka in a Group Two Super Eights match in Pallekele on Saturday.
Sri Lanka will need to address batting inconsistencies and adjust their bowling strategy in the absence of Wanindu Hasaranga as they prepare to face Oman in a crucial T20 World Cup Group B match.
In the final over, when the nerves jangled, it was Bangladesh who stayed composed and savoured the sweet taste of success. Sri Lanka's 8-match winning streak in the T20 Asia Cup came to a bitter end with this defeat.
Mathews made his T20 comeback for Sri Lanka in January after a three-year gap.
Injury-hit Australia are considering including veteran Steve Smith to strengthen their batting line-up for the crucial T20 World Cup Group B match against Sri Lanka. Australia needs to win to secure a spot in the Super Eights after a defeat to Zimbabwe.
Pakistan's chances of reaching the T20 World Cup semifinals depend on a dominant win against Sri Lanka and a significant victory for England against New Zealand. The team's batting woes and reliance on individual performances pose a challenge.
Sri Lanka ended on the wrong side of history, slumping to their second-lowest T20I total and lowest all-out total by a Test-playing nation against Zimbabwe in the second T20I at Harare on Saturday.
Sri Lanka defeated New Zealand via the Super Over in the opening Twenty20 international on Sunday for a 1-0 lead in the three-match series, as Charith Asalanka hit a half-century before guiding them home in the tie-breaker.
