Chandimal, who was appointed Test captain last month, missed the opening Test thrashing by India because of the illness.
He returns for the second of the three Tests. The hosts have also been boosted by veteran spinner Rangana Herath being declared fit after injuring his finger in the first game.
The International Cricket Council allowed Chandimal to use an inhaler to ease breathing while recovering from pneumonia.
Many inhalers contain substances that are banned by sporting authorities.
"I am much better. Thanks to the ICC they gave permission for me to use the inhaler, and that will help me breathe properly. Rangana is also fit to play," Chandimal told reporters on Wednesday.
Chandimal, who became skipper after Angelo Mathews quit following the team's humiliating one-day series defeat by Zimbabwe, hinted at playing two left-arm spinners at the Sinhalese Sports Club Ground.
Uncapped spinner Malinda Pushpakumara is set to make his Test debut in a team struggling with many injuries.
"Most probably Malinda will come into the side. Dhananjaya (de Silva) has more chance to replace Asela (Gunaratne). We'll have to see the surface," said Chandimal. Gunaratne broke a finger in the first Test.
World number one Test side India start as overwhelming favourites against seventh-ranked Sri Lanka, but Chandimal dismissed suggestions of a whitewash defeat in the series.
"Who is saying that? You can't say that. They are a very talented team, but we aren't going to lose 0-3," Chandimal said.
"We want to go and win. We are looking to give our best and win this game, level the series and then go to the third match. We have the determination to do that," he added.
First Published: August 2, 2017, 5:13 PM IST