South Africa one-day captain Temba Bavuma has been ruled out for the remainder of the Proteas' ODI series in Sri Lanka with a fractured thumb.

The skipper suffered the freak injury during Wednesday's first ODI that, inspired by centurion Avishka Fernando, the hosts won by 14 runs.

Bavuma was inadvertently struck from a fielder's throw-in during the 26th over at the R. Premadasa International Cricket Stadium.

Persistent discomfort saw him retire hurt two overs later, with scans later revealing a fracture.

Bavuma will return to South Africa for further treatment, from which his recovery time will be determined.

Keshav Maharaj will deputise as captain for the second ODI of the three-match series on Saturday.