In a wide-ranging interview with ESPNcricinfo, to be published this week, Arthur revealed that although Kusal Mendis
was not part of the West Indies tour - and is not expected to be named in the squad to play Bangladesh - he remained a player that Sri Lanka's coaching staff believe could play a major role in Sri Lanka's future.
"Oshada Fernando has shown signs of being a really good player going forward - certainly in that all-important No. 3 position," Arthur said. "I think Kusal Mendis is still all-round one of our best players. Getting him to deliver to his potential is at the forefront of my thinking.
"And I'm loving what I'm seeing of Pathum Nissanka at the moment. He'll carry Sri Lankan cricket forward - certainly in Test cricket, and he'll play a massive role in one-day cricket. How he develops his T20 cricket, time will tell."
Nissanka, 22, impressed in the recent Tests against West Indies, when he scored 9, 103 and 51, having come into the side with a first-class average in the mid 60s. Arthur said that among the new entrants to the Sri Lanka squad, Nissanka was unusual in that he did not appear to require intensive training to prepare him for the rigours of international cricket.
"Hasaranga's got that streak in him all good-quality players have, which is when the game gets tough, he wants the ball. When the game gets tough and he's batting, he wants to be there to hit the winning run. He's got that deep desire"
"For a long time, I hadn't seen Nissanka since I arrived in Sri Lanka. I'd heard about him, but when domestic cricket was being played after the first lockdown, he was injured," Arthur said. "So we put him in a larger training squad while we were preparing for the West Indies tour, and immediately I saw a boy that could play. I watched him for ten minutes in a net session and he looked the goods.
"He's a kind of a different beast because technically he's outstanding. Physically he's very good and his fielding standards are exactly where they need to be. He's slotted in nicely. Yes, we've had to chip away and polish a little bit, but whatever Nissanka did with his coaches through the ranks has been pretty good. They've prepared him very well for international cricket."
On the spin front, Arthur has repeatedly spoken highly of Hasaranga, who in the past year has become an all-format player. "Hasaranga's got that streak in him all good-quality players have, which is when the game gets tough, he wants the ball. When the game gets tough and he's batting, he wants to be there to hit the winning run. He's got that deep desire. He doesn't give a s**t, if you like. He's got that attitude. Any player who has that is gold.
"He wants to be making the decisive plays with bat, ball and hitting the stumps from cover point."
Left-arm spinner Embuldeniya, meanwhile, will not be part of the Bangladesh series on account of injury, but Arthur expected him to be a threat for Sri Lanka in the longest format. "Lasith Embuldeniya is going to be an incredible bowler. He's still young. He's still lacking just a little bit of confidence in his own ability. I don't think he knows yet how good he is. And with Hasaranga, you've also got the wristspin to go with the fingerspin of Embuldeniya."
Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @afidelf