"I've always felt like a Kiwi and always will.
"I've lived everywhere, leaving Russia as a 12-year-old, but I've never felt at home like I do in New Zealand."
Sitak has yet to make good on the potential he showed as a junior. At 12 his parents shipped him to a tennis academy in Germany.
They following year he was signed to international sports agency SFX which has had Jimmy Connors, Stefan Edberg and Andre Agassi on their books; and in 2001 he won the Orange Bowl, assuming the mantle as the world's No 1 14-year-old.
His intake that year included Rafael Nadal, Andy Murray and Novak Djokovic; but injuries and a slew of different coaches saw him slip off the radar and he's lived a nomadic existence, calling France, Germany, the US, Switzerland and Italy home.
Now it's Auckland, with artist wife Anya.
As his former countrymen freeze in -20C temperatures, Sitak is stripping down to his shorts and taking a daily dunk in the Pacific Ocean across the road from the New Zealand team's Mount Maunganui hotel.
Life in New Zealand is good and Sitak has even been learning the haka, which the players will pull out at tomorrow's draw, and hopefully again during Friday's opening ceremony.
"The first time I saw the All Blacks do it it was the coolest thing I'd seen, so to do it myself was amazing.
"The first practice went well although I don't know if four white boys doing it will have the same impact, but putting so much intensity and raw emotion into it gave me goose bumps."
Sitak's first ITF win as a junior was against Istomin (6-0 6-1) 13 years ago and he knows the Uzbekis' games well, not that it will be a leg-up in Tauranga this weekend.
"I know them all having played against them from when I was 12 to 14 years, but it's one thing to know them as juniors and a different story now so I wouldn't say there's any advantage because so much has changed."
Istomin's career earnings eclipse Sitak's modest income 20-fold but anything can happen in Davis Cup, and upsetting the world No 57's rhythm could be key to an unlikely win.
"Denis will be tough - he's played Federer and Nadal in grand slams on the big stage and played well against them, and came close to beating Tsonga a couple of weeks ago at the Australia Open, but Davis Cup's different than regular tournaments and if the crowd gets into it you never know how Denis will react and it could help us a lot.
"The key to winning is a big team effort, we've maintained that all along.
"We have four good players and everyone will be behind whoever's on court.
"In Davis Cup, more so than regular ATP, ties have gone against form and produced unbelievable five set matches."
At 348 in the world a year ago, Sitak has dropped to 425 but is still New Zealand's second-ranked player.
He's been as high as 299. Last year he set his sights on cracking the top 150 but went backwards, and quickly.
In 2012, which started with a loss in qualifying at the Heineken Open and failure to make the main draw at ATP Tour Challenger event in Hawaii and Tasmania, Sitak wants to give the top 200 a nudge and is prepared to eschew lower-tiered Futures events to give him a greater chance of shifting his career up a gear.
"The Heineken Open was a good lesson in playing on a big centre court and I made the decision from there to only play ATP events and big Challengers from now on because I need that experience of playing big stadiums and against top 100 players to get where I want to be."
It's a big dream and not without risk - Challenger tournaments mean weekend qualifying for players of Sitak's quality and failure means no ranking points and no pay cheque.
"It obviously depends on your age and what stage your career's at, and sometimes Futures are good if you're working on something in your game you want to take into a match.
"But I've played enough of them now and want to go bigger.
"There's obviously a big risk involved with playing only bigger events but I've seen people take the step and succeed.
"It could take a couple of months, maybe a few more, but I think I'm ready."