After a one-sided contest at Colombo, Karunaratne clarified to his teammates that he expects his batsmen to use their freedom with prudence.
"When I say players should be free, I don't mean that you just hit every ball that you see," he said.
"It's about keeping your mind free. If you at any time feel like you should play the reverse-sweep but you stop yourself, you're restricting yourself."
Karunaratne seemed vexed with the lack of cricketing nous and discipline exhibited by Sri Lanka during the lost encounter.
"There are times when you can get runs from that shot, and when it's a safe option. It's about being relaxed. Freedom doesn't mean swinging at every ball. It's about playing with confidence," he added.
After Sri Lanka's emphatic six-wicket win against New Zealand in the first Test, wicket-keeper Niroshan Dickwella had earlier reflected on the freedom players received under the leadership of Karunaratne.
"What Dimuth says is go and do what you want to do, and what you feel you can do. If we make a mistake, he'll pull us aside and say this happened, 'why don't we fix that mistake for next time?' He talks a lot about being confident about your abilities. And he gives you that confidence," wicketkeeper-batsman Dickwella remarked.
Karunaratne bemoaned Sri Lanka's inability to put up an impregnable first-innings lead, taking into consideration how New Zealand declared at a colossal 431/6 in their second innings. He gave a scathing analysis to his companions and shared a candid critique on his batsmen's reckless set of strokes.
"It was a pretty good wicket in the first innings, and we didn't execute our shots very well. The batsmen probably thought it was going to be a good, flat wicket and so the application wasn't there.
"At times I felt our players really lacked patience. A Test is a very valuable thing, and batsmen should know how to play according to the situation. They should know how to handle that freedom."
Sri Lanka started the second Test reasonably well, piling up 244 on the scoreboard. However, they lost their way in the middle as except for the captain's 65, Dhananjaya de Silva's first innings sublime century, and the gritty innings of 51 from Dickwella in the second innings, no other batsman made a substantial score.
Karunaratne highlighted his own error of judgment as well, saying: "Even me, after getting 60, I played a rash shot (in the first innings). It was a good wicket and you have to put up a good score on it. The Kiwis batted really well. They put up huge totals and put us under pressure."
Sri Lanka will now gear up for the three T20 Internationals in Pallekelle commencing from 1st September.