Vito, a star of last year's world series triumph, had been suffering a calf strain but appears to have overcome it after training well yesterday.
However, coach Gordon Tietjens has been forced to make a late change to the squad after Tu Umaga Marshall was ruled out of the tournament with a lower back strain.
He will be replaced by Julian Savea, also from Wellington.
Savea played the opening two tournaments of the 2008-2009 world Series in Dubai and George.
Tietjens said losing Umaga Marshall was a blow this close to the tournament, and adds to the miserable run of injuries which his squad has sustained in the lead-up to the World Cup -- skipper DJ Forbes and playmaker Tomasi Cama have only just recovered from injuries.
"I'm disappointed for Tu, who has worked hard to get ready for the World Cup.
"But like the earlier injuries, we have to move on and ensure we perform when the tournament starts on Thursday."
Forbes and Cama trained strongly in the Dubai heat this week.
"They're both fine, in fact they've trained the house down."
Vito, left the national sevens squad last year in a bid to make his mark in 15s rugby, after his bulldozing runs played a huge part in setting up New Zealand's successful season.
"It's good to be back and a great opportunity."
Expectations of the side would not be higher than the pressure the players would put on themselves to perform at this tournament, he added.
New Zealand open their campaign tomorrow morning against Italy, followed by the Arabian Gulf.
Tietjens needs Vito, Forbes and Cama fit and firing, with his side's imposing aura dulling somewhat with no wins from four International Rugby Board (IRB) tournaments in 2008-09.
The World Cup ends on Sunday.
Meanwhile, injuries have also forced changes to the New Zealand side for the women's sevens World Cup being played concurrently with the men's championship in Dubai.
Bay of Plenty's Exia Edwards fell ill soon after arriving in Dubai and has been hospitalised in Dubai with suspected kidney infection.
She will be replaced by Auckland's Angela McGregor, who will join the squad in Dubai today.
Coach Darryl Suasua said the main concern was for Edwards' health and ensuring she got the care she needed and so as to return to New Zealand as soon as possible.
"It's naturally a huge disappointment for Exia after all the hard work she has put in to prepare for this tournament."
Updated New Zealand sevens squads:
Men - Tomasi Cama (Manawatu), DJ Forbes (captain, Counties Manukau), Paul Grant (Otago), Nigel Hunt (Bay of Plenty), Zar Lawrence (Bay of Plenty), Tim Nanai Williams (Counties Manukau), Lote Raikabula (Manawatu), Julian Savea (Wellington), Ben Souness (Taranaki), Chad Tuoro (Counties Manukau), Victor Vito (Wellington), Viliame Waqaseduadua (North Harbour).
Women - Julie Ferguson (Hawke's Bay) Victoria Grant (Auckland), Carla Hohepa (Otago), Linda Itunu (Auckland), Justine Lavea (Auckland), Angela McGregor (Auckland), Huriana Manuel (Auckland), Hannah Porter (captain, Auckland), Teresa Te Tamaki (Auckland), Renee Wickliffe (Counties Manukau), Rachel Wikeepa (Waikato), Selica Winiata (Manawatu).
