Serena and Wozniacki were due to arrive in the early hours today with Venus scheduled to touch down a few hours after the duo.
The three players will have a light practice session later today, before resuming full training tomorrow.
The event has always drawn quality players, mainly due to a relaxed atmosphere, knowledgeable crowd and player-friendly facilities. But having three former world No1s - including arguably the greatest female player in history - is beyond comparison.
There have been some good fields in the last few years, especially since Venus has become a regular visitor, but the 2017 line-up is the best of the modern era, probably since the days when Margaret Court and Evonne Goolagong graced Stanley St.
For some perspective, look back a decade ago. The top seed in 2006 was Nadia Petrova, then ranked world No9. The Russian reached the semifinals of a grand slam on four occasions and won 13 WTA singles titles, but was never a household name. Compatriot Elena Likhovtseva (world No17) was second seed, coming off a year where she reached the last four at Roland Garros. But she never came close to such heights again, and became a doubles specialist. The other top players that year were Daniela Hantuchova (Slovakia) and glamorous Russian Maria Kirilenko. They were all decent names at the time - and that lineup was hailed as one of the best in the Classic's history - but the presence of Serena, Venus and Wozniacki is a whole new level.
Serena is the standout, a one of a kind player whose dominance we may never see again. She is among the true legends of the female game - alongside Martina Navratilova, Steffi Graf and Court - but her record during the most competitive era of the sport probably makes Serena the best ever. She won her first Grand Slam in New York in 1999, and has since accumulated 22 majors from 28 finals. Her longevity has been remarkable, with nine grand slams singles titles since she turned 30. Serena is also the oldest player to attain the No1 ranking, and has reached seven of the last nine major finals, winning five. She has reigned supreme over three generations of female players and will commence her 21st season as a professional next year.
Venus is likely to be overshadowed by Serena during this visit but that shouldn't diminish from her status as one of the greats. Perhaps the most impressive aspect about the older Williams sibling is the way she has managed to defy time, and her serious immune illness. She was supposed to be in the twilight of her career when she first came to Auckland in 2014, but since then has won five more WTA titles, become only the fifth player in tennis history to be ranked inside the top 10 as a 35-year-old and made a fairytale run to the Wimbledon semifinals earlier this year.
Wozniacki was blighted by injuries in the 2016 season, but reached the last four at the US Open and won titles in Tokyo and Hong Kong. The Dane told the NZ Herald last week she believes "she can still beat anybody on her day" and will be looking for her first title on her fourth visit to Auckland.
