"It's always good having new and exciting youngsters coming into the side," Tietjens said.
"Reiko is a very quick and agile player with a great step and vision. He has lots of pace and has really impressed me. Dylan really excelled at the nationals. He is a big forward, has great offloading skills and is very fit. He is new to the game, but has still performed exceedingly well.
"Beaudein Waaka also has a great step. He is very exciting to watch and I think he will open a few eyes this weekend. Jack has improved over the last 12 months at a huge rate. He is very fit and a great defender so will add real value."
New Zealand come in to the Wellington tournament, the fourth of nine in the world series, in need of a good showing given they're in third place on the overall standings behind South Africa and Fiji. New Zealand need to finish inside the top four this season to ensure they automatically qualify for next year's Rio Olympics.
"We are defending champions in Wellington so there's a lot to play for and it's always exciting to come to Wellington with the support we have here," Tietjens said.
"To perform well is top of our agenda. We got beaten by South Africa in South Africa in the last tournament. But we are on the improve and I would like think we can really nail it at this tournament. Winning Wellington will go a long way to adding a few more points to the ladder and towards qualification for the Olympics."
New Zealand trained in wet conditions at Porirua Park today, which is the sort of weather that could greet the sides this weekend, according to the long-range forecast.
New Zealand sevens squad for Wellington tournament: Dylan Collier, Scott Curry, Ambrose Curtis, Sam Dickson, DJ Forbes (c), Jack Goodhue, Rieko Ioane, Gillies Kaka, Tim Mikkelson, Sherwin Stowers, Beaudein Waaka, Joe Webber