"Surely the organisers can find another fighter instead of Whetu ... there must be plenty out there prepared to get in the ring for the cause," one texter stated.
Another texter questioned whether Raglan-based Barber would be fit enough to fight after being banned from rugby for so long.
"Let's face it ... Whetu was never one for fitness when he was a Magpie," he said.
One of the event's organisers, Magpies halfback Chris Eaton, who will also fight on the night, said he had no qualms about offering Barber a fight when his former MAC teammate Everard Reid withdrew with a shoulder injury.
"Whetu is a former Magpies teammate of mine. I don't agree with what he has done. But he has been given his punishment and everyone deserves a second chance," Eaton said.
The Barber-Hall bout is one of 14 on the card. In addition to the Waikato Rugby Union life ban last year, Barber was also banned by his Otorohanga club.
Waikato Rugby Union operations manager Bill Heslop said last night he didn't have a problem with Barber stepping into the ring.
"We banned him from rugby, not boxing. It's up to him. I'm sure he will go well and we wish him well."
Eaton and his brother, Kim, are organising the event as a fundraiser for the Jarrod Cunningham Trust and Kim's Auckland-based 9-year-old niece, Lili Reynolds, who was diagnosed with a brain tumour when she was 5.
Last year Lili was chosen by the Make a Wish Foundation and Team New Zealand to present the Duchess of Cambridge with a posy of flowers before she went sailing in Auckland.
In the feature bout, professional kickboxer Angus Benson will take on another kickboxer, Shaun Rankin, who is no stranger to success on the Hawke's Bay charity boxing scene. They were teammates in the Maraenui division-three rugby side last season after Benson stepped down a couple of grades from the Napier Technical premiers so he could devote more time to his kickboxing.