Defending champion Roberto Bautista Agut is the top seed for January's ASB men's tennis classic, with the full field just released.
The world number 14 is one of two top 20 players alongside 19th ranked John Isner, but the tournament drawcard, Argentine Juan Martin del Potro, is unseeded.
On Monday, del Potro capped his stellar year by inspiring Argentina to their first Davis Cup victory.
Del Potro fought back from two sets down to beat world no. 6 Marin Cilic in five sets, and almost five hours, in what he called, one of the biggest wins of his career. Since June, he has also beaten two current world number ones in Andy Murray and Novak Djokovic, as well as Stan Wawrinka and Rafael Nadal.
"His year has been incredible, especially to beat two current world number ones. He
is back winning ATP tour titles and just steered Argentina to their first Davis Cup crown.
It's a hell of a comeback. He is the player that none of the big four want to draw in Melbourne," said Tournament Director Karl Budge.
Listen: Karl Budge with Matt Brown
Del Potro is ranked 38 in the world with Cyprus' Marcos Baghdatis the eighth and final seed at 36.
Four of the top six seeds are Spaniards, with Bautista Agut joined by David Ferrer, Albert Ramos-Vinolas and Feliciano Lopez.
Former champions Jiri Vesely and Tommy Robredo are also returning to Auckland.
Full list of players
1. Roberto Bautista Agut ESP (14)
2. John Isner USA (19)
3. David Ferrer ESP (21)
4. Jack Sock USA (23)
5. Albert Ramos‐Vinolas ESP (27)
6. Feliciano Lopez ESP (28)
7. Steve Johnson USA (33)
8. Marcos Baghdatis CYP (36)
9. Juan Martin Del Potro ARG (38)
10. Joao Sousa POR (43)
11. Diego Schwartzman ARG (52)
12. Karen Khachanov RUS (53)
13. Stephane Robert FRA (54)
14. Jiri Vesely CZE (55)
15. Bagnis Facundo ARG (56)
16. Tommy Robredo ESP (57)
17. Malek Jaziri TUN (58)
18. Robin Haase NED (59)
19. Adrian Mannarino FRA (60)
20. Taylor Fritz USA (76)