Dinesh Chandimal said Ravindra Jadeja's suspension has given Sri Lanka a lift and his side have "something up our sleeves" as they attempt to deny India a Test series whitewash.
India spinner Jadeja was banned for the third and final match of the series after racking up six demerit points in the last two years.
The top-ranked Test bowler's latest offence came on day three of the second Test in Colombo, which India won emphatically to wrap up the series with one match to play.
Jadeja was named man of the match in India's latest crushing win and Sri Lanka captain Chandimal is relieved he will miss out in Pallekele, where the hosts will set about trying to salvage some pride on Saturday.
"We are two down but still we are a really good team and are hoping to win this game." said Chandimal.
"If we can do that, definitely we can get more confidence and move forward.
"We all know he [Jadeja] is the number one bowler at the moment. It gives us a bit of confidence - bit unfortunate for you [India] guys. As a team, we have something up our sleeves."
Chandimal bemoaned Sri Lanka's bad luck with injuries in a one-sided series, having lost Asela Gunaratne, Nuwan Pradeep and Rangana Herath.
He added: "India are a really good team, especially in the last two to three years, [but] every time players of my team are getting injured. We cannot get the combination right.
"Especially if you lose players like Rangana, Nuwan Pradeep and Asela. We are struggling because of that, but we don't want to give excuses."