Mathews hopes SL's seniors will step up
Chandimal was only elevated to the opening position in February, and Thirimanne had not originally been picked for the World Twenty20, but both batsmen come into the tournament with some form. Chandimal struck two fifties and a 37 during the Asia Cup, while Thirimanne top-scored for Sri Lanka in each of the warm-up encounters preceding their tournament - hitting 41 against New Zealand, and 45 against Pakistan.
"They are two very good players and they read the game and situations very well," Mathews said. "Chandimal, we saw in the last match and all through the Asia Cup - he has been batting really well. And Thirimanne has so far batted the best in India - he has batted the best out of the lot. Those two are very talented players so we bank on them. We trust them. As seniors they will take on the challenge and hopefully they will deliver."
Further down the batting order, Sri Lanka have suffered several collapses in recent weeks. In the Asia Cup clash against Bangladesh, Sri Lanka were 75 for 1, but soon slipped to 102 for 6. Part of the reason for these middle-order slumps has been Mathews' recent inability to convert starts - a trend he feels he needs to turn around, as the most experienced batsman in the middle order.
"Myself, yes, I had a kind of a lean patch in the recent past as well," Mathews said. "I've been batting well in the nets so hopefully I can carry that through to the games."
On the bowling front, Mathews has been playing a vital role, delivering cheap, and often probing overs early on. It is a role he is set to continue, particularly as his cutters and slower balls are likely to be productive on Indian surfaces. "Generally India is a really hard place for the bowlers," he said. "Even for the faster bowlers, if you are smart enough and you have the variation, you can still get away. It depends on the wickets that we play. In Kolkata it is a bit slower than the other parts of India."
Mathews said he would look to Rangana Herath for wickets on pitches that are likely to be given to turn. "We still want him to be an attacking spinner," Mathews said. "He's our main spinner and is very experienced. We want him to take wickets through the middle. If we need him to contain, he can contain as well, because he has the experience of adapting himself when the occasion requires, on certain wicket. That adaptability is in him."
Afghanistan, Mathews' first opponents, had Sri Lanka in trouble during last year's World Cup, removing the team's first four wickets for 51, after they had made 232. Mathews said that experience had underlined how wary his team must be of Afghanistan's quality.
"They are very tough. The last two times that we played it was two close games. They have fought really hard against us and we had to fight to beat them. We can't really call Afghanistan minnows. They've beaten all the teams in their qualifying changes very easily. We don't take them easily, because they can upset any team on a given day. We have to play really good cricket to beat Afghanistan."
Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @andrewffernando