Of all the puzzles faced by Ricki Herbert over the next year, one of the most fascinating is who he elects to use in a defensive midfield role for the All Whites.
In a team that will rarely dominate possession, especially against higher-ranked opponents, the need for someone capable of providing a defensive shield in front of the backline is vital.
In the past, New Zealand has produced plenty of these grafters; tough tackling men who will work their socks off in the engine room. Think of Keith 'Buzzer' McKay, Duncan Cole, Allan Boath and Robert Ironside among many others.
In more recent years Chris Jackson, Jeremy Christie, Simon Elliott and Tim Brown have filled the holding role.
But at the moment, there are no stand-out specialists.
"It's certainly an area of the park that we're not overly strong in from a numbers point of view," says Herbert.
"[With someone like] Michael McGlinchey, obviously he's got a great chance to be in there and I guess we [would] have a different way of being able to play. I think Ivan [Vicelich] could sit in there and do a holding role for us and allow some younger, quicker players to play in front of them.
Hopefully [with] the Olympic campaign, maybe a couple of the younger players there do a really good job and we can move them further forward as well. We've got one or two permutations."
US-based Dan Keat, who will miss the matches against El Salvador and Honduras due to club commitments, is a possibility but his first instinct is to attack. As Herbert indicated, McGlinchey, on the back of his stellar season with the Central Coast Mariners, has a strong case but he is the creative type whose best work is done in the opposition half.
Vicelich did a solid job in South Africa in the centre of the park and is one of Herbert's most reliable lieutenants. He could probably do the job over the next few weeks but the 35-year-old can't go on forever.
Oly-Whites captain Adam McGeorge gets his chance after being added to the squad on Friday but he has yet to prove he is capable of such a large step up.
It seems Herbert is in the mood for experimentation as he looks ahead to the possibility of up to seven games in a little over a fortnight.
"Without making promises, I think there will be opportunities," says Herbert. "It's going to be a very tough, intensive time period. If you go right through to the final at the [Nations Cup], you've got five games in 10 days. That's going to have its demands, let alone the heat and the travel of the guys coming in."
So there may be room for some experimentation, especially in one or two of the group games at the Nations Cup. Michael Boxall could be shifted from his current defensive role into midfield. The 1.88m Boxall, currently with the Vancouver Whitecaps, has always looked a player with potential; one whose skill-set could adjust to the international stage. The 23-year-old, who played a pivotal role in New Zealand's 2008 Olympic campaign, made his All Whites debut against China last year. Herbert seems a fan.
"We didn't use him in the recent game at home," says Herbert. "It'll be good to have [Boxall] back in the squad. I thought he was very good against the Australians [last year] in a pretty depleted side."
For a left-field suggestion, what about Winston Reid being used in a midfield role? The 23-year-old, who was expected to play in West Ham's Premier League promotion play-off final against Blackpool overnight, has improved over the past season in the demanding arena of the Championship. It sharpened up his overall game and tactical awareness.
He would bring a physical presence, with a style perhaps in the mould of Patrick Vieira. There are questions about his distribution and vision - and he may still be prone to the odd rash decision - but it could be an experiment worth trying.
Another subplot on tour will be the development of Ian Hogg, who was added to the squad along with McGeorge. With the absence of Tony Lochhead for the US leg, the highly-rated Auckland City left-sided defender should get his chance.