Sri Lanka were thumped by 10 wickets in their opening match against New Zealand in Cardiff on Saturday.
Sri Lanka were routed for a paltry 136, giving their bowlers little chance, and New Zealand's opening pair of Martin Guptill and Colin Munro coasted to their target in the 17th over.
Malinga said Sri Lanka had talent in their ranks but were short of experience in the conditions they were facing in England and Wales.
"Bowlers have a big role to play in tomorrow's game (also in Cardiff). We never know what's going on, who is bowling first or second," he said.
"But still, bowlers can change the game. I still believe that. Then I feel players need to get confidence, but we can improve our skills at the moment.
"We need to get mentally tough. And all the pressure is with us, yes, but we have to play with a free mind and do our best in tomorrow's game."
Sri Lanka have won only one of their 10 ODIs this year -- against minnows Scotland.
"I feel we have talent but not much experience of these conditions," said Malinga.
The bowler backed skipper Dimuth Karunaratne to anchor the innings, as he did with his 52 not out against New Zealand.
"We see that Dimuth has good temperament to play in these conditions," said Malinga of his skipper.
"I feel we have also top seven batsmen who have to take more responsibility and patience."