Joseph Parker's camp has revealed that the fighter underwent surgery on his elbows late last year.
Trainer Kevin Barry says the WBO Heavyweight Boxing champion has been nursing pain and restriction in both his elbows for more than two years.
In November 2017, the team elected to have one of New Zealand's best orthopaedic surgeons Craig Ball, to correct the injuries.
The announcement was made on the eve of Parker's unification bout with Anthony Joshua in Cardiff.
"We're pretty transparent, we've got nothing to hide, especially given it was so damn successful," Parker's promoter David Higgins said.
"We were negotiating while Joseph was having surgery, but now seems like an opportune time to end speculation and front foot the issue."
Barry is delighted to confirm the results of the surgery have been nothing less than fantastic with Parker regaining maximum speed and power for the first time since 2016.
"I think it was a very important decision for us to make. We've had a lot of pain in the last two years, and I believe it has really impinged his performances," Barry said.
"We have been managing pain in nearly every single training camp, and for us now to go into a camp for the biggest fight of Joe's career, and have no pain at all, it was a very good move for us getting the surgery."
The team says the timing of the surgery was determined by his fight schedule in 2016 and 2017.
Barry says the elbow problems did have a bearing on Parker's performance over the last year.