Sri Lanka sacks skipper Dinesh Chandimal after Test debacles
Chandimal, 29, was replaced by Dimuth Karunaratne, Sri Lanka Cricket said, listing a 17-member squad that did not include the right-handed batsman.
National selectors said in a statement Chandimal was dismissed to help him "regain his form and be ready for future international tours."
His sudden sacking came a day after he insisted his team could lift their game during their upcoming tour against South Africa, following a thrashing by Australia.
Under Chandimal, Sri Lanka lost the opening day-night Test in Brisbane by an innings and 40 runs inside three days and followed it up with a 366-run thrashing in the Canberra Test.
It extended a dire run of results for troubled Sri Lanka who have been hit by injuries and off-field scandals.
Besides the defeats in Australia, Sri Lanka also recently lost a home Test series to England 3-0 and suffered a 1-0 loss against New Zealand in an away series.
The first Test in South Africa starts on February 13, with the squad flying straight there from Australia this week in a gruelling overseas schedule.
"We are a young team and we are always learning how to play, especially in these tough conditions. We will bounce back in South Africa," Chandimal said in Australia.
"South Africa is similar to these conditions and with very good bowlers. We know that as a team we have to play in tough conditions and we need to adjust to those conditions and step up as a team."
Sri Lanka Test squad: Dimuth Karunaratne (stand-in captain), Niroshan Dickwella (vice captain), Lahiru Thirimanne, Kaushal Silva, Kusal Mendis, Kusal Janith Perera, Milinda Siriwardana, Dhananjaya de Silva, Oshada Fernando, Angelo Perera, Suranga Lakmal, Kasun Rajitha, Vishwa Fernando, Chamika Karunaratne, Mohamed Shiraz, Lakshan Sandakan and Lasith Embuldeniya.