New Zealand have been dealt a blow on the eve of the Emirates Airline Dubai Sevens with captain Tafai Ioasa ruled out of the tournament after twisting his knee when he landed awkwardly in training on Thursday.

Ioasa missed six of the eight tournaments last season with a knee injury, but coach Gordon Tietjens revealed it was the 27-year-old forward's other knee that suffered the damage in a "freakish accident".

"That is really surprising, it's his other knee. The funny thing was we never had the ball, he was just competing in the team's lineout and twisted his knee, that's really the extent of it," Tietjens told "He wasn't being tackled, just coming out of a lineout so it was quite a freakish accident really.

"Obviously it happened at training today, it was probably just a real freak accident, but it's really disappointing and Tafai was shattered when he came down and has done some medial ligaments on one knee, ruling him out of this tournament and possibly South Africa as well.

"It is quite disruptive, he is our captain, he was keen to get back playing in the World Series after he missed six tournaments last year, so it was quite disruptive for the other players.

Standing in the wings

"We won't know the extent of the injury until a couple of days, then we'll make a decision whether to fly him on the South Africa. We hope he will be ok, but at the moment indications are it possibly doesn't look too good."

Tietjens admitted he is "lucky enough" to have DJ Forbes to take over the captaincy, something he did in the six tournaments Ioasa missed last season as New Zealand came from behind to win the final two events and pip Fiji to claim a seventh Series title in eight years.

Ioasa's place in the squad has been taken by newcomer James Kamana, who was due to play in the social tournament on Thursday before joining the camp for the event in George when Nigel Hunt flies home after Dubai on paternity leave.

The loss of Ioasa is another blow to New Zealand, who had already travelled to Dubai without their IRB Sevens Player of the Year Afeleke Pelenise, the scorer of 41 tries last season who is currently sidelined with a knee injury.

However while New Zealand will be missing two of their stars, Samoa can boast Mikaele Pesamino in their ranks for the Series opener, which kicks off at Dubai Exiles Rugby ground on Friday at 09:30 local time when Scotland face New Zealand.

Samoa welcome back try sensation

Pesamino was the leading try scorer last season with 43 and now joins the likes of Uale Mai and Lolo Lui in an experienced Samoan line-up, having not been named in new coach Rudi Moors& initial squad earlier this month.

However Samoa, who captured their first ever Cup title in Wellington last year and finished third overall behind New Zealand and Fiji, did lose the services of promising youngster Alatasi Tupou to illness before their departure.

A couple of other changes made since the squads were announced over the last few weeks are Nick Wakely replacing Dafydd Hewitt in the Welsh ranks and Peter Owens stepping in for 18 year old Junior Sovala in the Australian squad.

Tunisia meanwhile have named only one newcomer in their 12-man squad in Aymen Gloulou, unlike their fellow Africans in Zimbabwe who will have half of their squad making their IRB Sevens World Series debuts in Dubai.

The host Union, the Arabian Gulf, have three newcomers in their squad in Corry Oliver, Stuart Gibb and Ayman Razek, while two of Canada’s three new faces were members of their Rugby World Cup 2007 squad in Sean Michael Stephen and Daniel van der Merwe.

Click here to view all of the squads.