Mathews has not had the captaincy officially stripped from him since he was re-appointed to the role in January but injuries have prevented him from actually leading the side out onto the park.
With stand-in skipper Dinesh Chandimal banned for Four ODIS Sri Lanka cricket have not had to make any tough decisions just yet.
The only completely uncapped member of the squad led by Mathews will be left-arm spinner Prabath Jayasuriya, who has kept himself on the selectors radar with steady displays in domestic cricket.
Paceman Kasun Rajitha gave a good account of himself in his debut Test series against the West Indies and could be in line to make his ODI nod.
Dusmantha Chameera has fallen victim to the axe despite taking 2/17 in 8 overs in Sri Lanka’s last ODI assignment back in January.
Chameera is one of six players who took part in a tri-series involving Zimbabwe and Bangladesh which Sri Lanka won.
Experienced allrounder Asela Gunaratne also misses out though his struggles with form and fitness make the decision less surprising.
Opener Danushka Gunathilaka was suspended from all international formats by SLC pending the outcome of a disciplinary hearing and he will take no part in the series though Jeffery Vandersay, who was the subject of SLC discipline recently has been named among the players on standby.
Pacemen Nuwan Pradeep and Shehan Madhushanka have made way as well alongside legspinner Wanindu Hasaranga.
Akila Dananjaya and Lakshan Sandakan are likely to hold the key for Sri Lanka in this series as the frontline spinners but they will have plenty of backup in a squad loaded with allrounders.
Shehan Jayasuriya and Dasun Shanaka are among the allrounders brought into the group to face South Africa while Dhananjaya De Silva, Mathews and Thisara Perera can all do a job with both bat and ball.
Opener Dimuth Karunaratne, paceman Isuru Udana and 20-year-old off-spinner Nishan Peiris join Vandersay as players on standby.
The first of five ODIs against South Africa is slated to take place on Sunday July 29 in Dambulla.
Sri Lanka squad: 1 Angelo Mathews (capt.) , 2 Dasun Shanaka, 3 Kusal Perera, 4 Dhananjaya De Silva, 5 Upul Tharanga, 6 Kusal Mendis, 7 Thisara Perera, 8 Niroshan Dickwella, 9 Suranga Lakmal, 10 Lahiru Kumara, 11 Kasun Rajitha, 12 Akila Dananjaya, 13 Prabath Jayasuriya, 14 Lakshan Sandakan, 15 Shehan Jayasuriya
(Courtesy Cricket 365)