"We were actually only told late last night - the blood Test came a bit late. He's got pneumonia," Asanka Gurusinha, Sri Lanka's cricket manager, said of Chandimal on Friday. "He was admitted to hospital this morning at 9am, and he's definitely out of the first Test.
"The doctors have advised us this morning to say: 'Finish the first Test' and they'll advise us afterwards. If they tell us he needs another week to recover, that's it. We can't do anything."
Chandimal's absence is a significant blow to the Sri Lanka team. Not only is he the new captain, he is also part of a relatively-settled top order. Although limited-overs captain Upul Tharanga is also in the side, Herath's experience as Test captain may land him the role. He most recently led the side in the 1-1 draw against Bangladesh, in March.
"Most probably the captain is going to be Rangana, because for now it's just one Test, and he has done the job before," Gurusinha said. "But we haven't worked everything out. We will sit down and do that this afternoon."
The news is slightly better for Sri Lanka elsewhere on the injury front. Asela Gunaratne, who had experienced tightness in the hamstring during the Zimbabwe Test, is likely to be available for the match. "He's good - we got the green light from the physio this morning, but we'll still have to put him through his paces over the next few days," Gurusinha said. "Asela is a very resilient guy. Very tough."
Fast bowler Nuwan Pradeep, who had also missed the Zimbabwe Test also with a hamstring injury, has recovered sufficiently to be named in the squad Gurusinha confirmed. The full squad is expected to be announced late on Friday.
One of Chandimal's best Test innings had come against India in Galle. In 2015, his 162 not out had helped Sri Lanka overturn a 193-run first-innings deficit.