Both Berman and Nathan are adamant that, as interim champion, Budler has already added the WBA belt to his IBO title, after the former became vacant.
“That is in accordance with the WBA’s own rules,” Berman said ahead of the fight.
The official website of the WBA, however, disputes this view, proclaiming the strawweight title is vacant and that Budler and Diaz are fighting for the vacant title.
Either way, the winner on Saturday will be regarded as the WBA and IBO champion, not only by Berman and Nathan but by both organisations as well.
Ensuring the authenticity of the showdown, both Budler and Diaz comfortably made the strawweight limit at Friday’s weigh-in.
There was a moment of drama, however, when Wilberforce Shihepo stepped onto the scale for his light-heavyweight bout for the WBC silver title against Johnny Muller.
Shihepo had weighed in a disturbing 6kg over the limit at the pre-medical weigh-in on Tuesday and surprised all and sundry by making the limit at the first time of asking on this occasion.
Meanwhile, the two-week postponement of the Golden Gloves tournament has been “a blessing in disguise” for Budler.
“I always make a point of being in good shape, whether in training for a fight or not,” Budler said.
“But the extra two weeks of preparation has enabled me to reach a new level of fitness and I’m just raring to go.
“The only negative effect of the delay is that I have been impatient and itching to get into the ring after the extra wait.”
Nathan said while Budler had never looked better in training, Colombian Diaz was a dangerous opponent who will not be under-estimated.
“With 14 knockouts among his 21 victories, he is clearly a dangerous puncher and Hekkie will be taking no chances,” Nathan said.
“We’ve watched videos of his previous fights and he is a good mover who knows how to gauge his punching range.”
Diaz has lost four of his previous 25 fights, while Budler has only been beaten once in a career that has gained new momentum in the last 12 months.
Budler is rated as the top strawweight by both the WBA and IBO, while Diaz is fifth in the division by the WBA and eighth by the IBO.
The Colombian has yet to beat an opponent ranked among the top 10 in the world during his 25-bout career.
Also on Saturday’s bill, Ryno Liebenberg will come up against Joey Vegas of Uganda for the WBC international light-heavyweight title.
Unlike previous tournaments at Emperors Palace, which have been held in the main Convention Centre, Saturday’s programme will be staged at the more compact Theatre of Marcellus arena.
Emperors Palace programme: Featherweight: (four rounds) Phumudzo Monyai v Ricardo Hiraman.
Junior welterweight: (six rounds) Jeff Otembio v Adam De Moor.
WBC silver light-heavyweight title: (12 rounds) Wilberforce Shihepo (Namibia) v Johnny Muller (South Africa).
WBA/IBO strawweight title: (12 rounds) Karluis Diaz (Colombia) v Hekkie Budler (South Africa).
WBC international light-heavyweight title: (12 rounds) Joey Vegas (Uganda) v Ryno Liebenberg (South Africa).