The Proteas have lost a considerable amount of experience for the upcoming tournament in England with Smith injured and Kallis opting out for personal reasons.
Limited-overs skipper De Villiers, speaking at his side's arrival press conference in London, said: "I see it as an opportunity. I think there is a very good energy in the team.
"Graeme and Jacques will be missed experience-wise, they've played for a long time.
"But I like to look at things in a positive way.
"There is a lot of energy coming in a guy like David Miller. We saw him in many games in the IPL, and he brings a lot of confidence to the team.
"To have an added number six or seven in our batting line-up, to know that we can win a game from anywhere, is great.
"And, obviously, Alviro Petersen comes in with a lot of experience.
"He's shown before in the shorter division that he can play the game really well.
"It's nice to have those two guys on the team. So I look at it from a positive perspective and I feel we have a great energy and great mix on the team."
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