Three Sri Lankan batsmen were able to collect more than 100 runs in the series as compared to Bangladesh's one.
On Wednesday, Sri Lanka got close to 300 on the back of a combined batting performance, headlined by Angelo Mathew's 87, before an opening burst from Kasun Rajitha and three wickets from Dasun Shanaka put paid to the Tigers' hopes of a consolation win in the final match of the series.
The hosts would also take heart from the fact that Mathews carried his late World Cup form to finish as the highest run-scorer from either side. It was just the kind of performance that Sri Lanka needed from a senior player after losing their star bowler Lasith Malinga.
"The young players grabbed their chances really well," the ICC website quoted Karunaratne as saying after the third match. "If there's a lot of competition and there's a strong bench, if a player is injured I can easily bring another player.
"I think this is the way we have to build a good line-up. This is the time we have to bring some youngsters for the next couple of years. We've had an issue recently, where we didn't have that strong bench. But players are now ready, and they'll grab the chances that come their way," he added.
The Sri Lanka skipper also said that players such as Niroshan Dickwella and Danushka Gunathilaka, both of whom have spent the last few months out of the team, will add to the wide pool of talent available to tap into as the island nation build and plan for the next four-year cycle, culminating in the World Cup 2023.
"You need a lot of players to build up that competition within a team so that players are constantly putting pressure on each other to perform," said Karunaratne.
"If you have a strong bench, the players who are in the team have to take that responsibility. There are a lot of players trying to get that chance, so there's pressure on the XI. I have a team I can work with. The youngsters have a great energy about them as well," he added.
The 31-year-old, however, insisted that they need bowlers who have the ability of picking up wickets at crucial junctures of the game, especially following Malinga's retirement from ODI cricket.
"We need to find bowlers who can get us wickets. We have to find those players who deliver in tough situations," he said.
Now, Sri Lanka will face New Zealand in the two-match series beginning August 14 at Galle.
( With inputs from IANS )