Lambie was appointed captain for the 2016 tournament as well, but he missed a large chunk of his team's campaign because of injury.
"Pat's talent, temperament and outstanding character makes him an automatic choice," said Du Preez. "He's a natural leader, who provides great inspiration and motivation for our young players and he has all the qualities needed to be a great captain.
"He has supported this team all his life and understands our unique culture, which has been built on the emphasis of a strong work ethic. Pat puts in the hard yards, leads by example and he has the respect and backing of everyone around him."
Commenting on his appointment, Lambie said: "It is a huge honour for me to again captain the Sharks. I would like to thank our management for affording me the honour of leading a relatively young, but exciting and talented team.
“With honour comes responsibility and together with the other leaders in the team, we will provide guidance and support to our young players.
"There is an exciting vision that we are working towards, that has been built on our core values, and we look forward to the support of our community, who are instrumental to our success."
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