The former champions easily got past Namibia and Ireland to make it to the tournament-proper but the lack of form of Kusal Perera and Dinesh Chandimal would be a worry for them.
Both Sri Lanka and Ireland have come into the match high on confidence after convincing seven-wicket wins against Namibia and Netherlands respectively in their lung openers.
Sri Lanka vs South Africa: Aiden Markram sets up 28-run win as Proteas go 1-0 up in T20I leg of tour
Markram's 33-ball knock guided South Africa to 163-5, a total they defended by restricting Sri Lanka to 135-6 to lead the three-match series 1-0 in Colombo.
Highlights, Sri Lanka vs South Africa, 1st T20I at Colombo, Full Cricket Score: Proteas win by 28 runs
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India vs Sri Lanka: Dasun Shanaka set to replace Kusal Perera as captain ahead of limited-overs series, says report
The 29-year-old, an explosive batsman and a seam bowler, will become Sri Lanka's sixth captain in less than four years if he gets the job.
Sri Lanka left Mathews, Karunaratne, Dinesh Chandimal and other senior players behind for their three one-day internationals in Bangladesh.
West Indies vs Sri Lanka: Dimuth Karunaratne leads visitors' resistance on Day 5 of drawn second Test
Set a daunting target of 377 and resuming at 29 without loss, the tourists reached 193 for two with a tops score of 75 by captain Dimuth Karunaratne and an unbeaten 66 by Oshada Fernando leading the resistance.
West Indies vs Sri Lanka: Pathum Nissanka shows defiance as visitors trail by 104 runs on rain-affected Day 3
Pathum Nissanka kept the West Indies at bay, with Sri Lanka limping to the close at 250 for eight in reply to the home side's first-innings total of 354 on a rain-affected third day of the second and final Test in Antigua.
West Indies vs Sri Lanka: Jason Holder stars with five-wicket haul as hosts take control of first Test
Jason Holder took five wickets to help bowl out Sri Lanka for 169. West Indies finished Day 1 on 13/0.
West Indies vs Sri Lanka: Evin Lewis stars with ton as Windies claim thrilling five-wicket win, clinch series 2-0
Lewis' hundred, which came off 121 balls and was embellished by eight fours and four sixes, earned him the Man of the Match award.
West Indies vs Sri Lanka: Fabian Allen's late heroics helps hosts clinch three-wicket win in 3rd T20I, secure 2-1 series win
The two sides will now play three ODIs and two Tests, all in Antigua.
Highlights, Sri Lanka vs England, 2nd Test, Day 2 at Galle, Full Cricket Score: Visitors score 98/2 at stumps
Mathews came in to bat at 7-2 after James Anderson had dismissed both Kusal Perera (6) and Oshada Fernando (0) in the morning session.
Sri Lanka vs England: Angelo Mathews leads hosts' fightback with an unbeaten century on Day 1 of second Test
Mathews built crucial partnerships, including a 117-run stand for the fourth wicket with skipper Dinesh Chandimal who made 52.
Highlights, Sri Lanka vs England, 1st Test, Day 3 at Galle, Full Cricket Score: Resilient Hosts reach 156/2 at stumps
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Sri Lanka vs England: Off-spinner Dom Bess' five-fer sees visitors gain upper hand on day 1 of first Test
Bess, who returned figures of 5-30, combined with paceman Stuart Broad, who took three wickets, as Sri Lanka were all out in two sessions as the two-Test series resumed in Galle after the original tour was aborted over the coronavirus in March.
Sri Lanka vs England, Highlights, 1st Test, Day 1 at Galle: Dom Bess five-fer powers visitors to commanding position
Follow live scorecard and ball-by-ball commentary from Day 1 of first Test between Sri Lanka and England
South Africa vs Sri Lanka: Hosts to rest Kagiso Rabada in second Test to ensure paceman's availability for Pakistan series
Cricket South Africa announced on Saturday that Rabada will not play at the Wanderers Stadium with a view to him being fully fit for the forthcoming series against Pakistan and Australia.
Highlights, South Africa vs Sri Lanka, 1st Test Day 4 at Centurion, Full Cricket Score: Hosts win by an innings and 45 runs
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