When Joseph Parker steps in the ring tonight against Dillian Whyte he’ll have a very important person manning his corner; his brother, and fellow pro boxer, John.

The 24-year-old cruiserweight currently boasts a professional record of three fights and three wins, appearing each time on his brother’s undercard.

His big break fell into his lap when it was announced that Joseph would be taking part in a massive unification bout against British champion Anthony Joshua at Cardiff’s Principality Stadium in late March. The younger Parker brother was pencilled in to appear on the undercard, giving him the chance to showcase his talents with the eyes of the boxing world watching.

But weeks away from what would have been the biggest night of his professional life came the crushing news that he would be lucky to ever set foot in a ring again, much less climb through the ropes on March 31st.

He was diagnosed with a brain aneurysm which scuppered all and any short term plans John had of lacing up his gloves.

An aneurysm is a weak spot on a blood vessel wall that can cause a bubble-like bulge. Often symptom-free, they can, however, be deadly if they burst.

In John Parker’s case, the options are stark; go under the knife, or hang up the gloves.

"When I found out, I was like 'can I still fight?' They were ‘nah, nah, nah, this is serious’," Parker said.

"So I went back in and told Joe and he was like 'are you all right?' ‘Yeah man, stuff this – I'm not going to let this aneurysm get me’."

But the initial defiance in the face of such devastating news soon gave way to the harsh realities of what the diagnosis meant.

The surgical options on the table are both invasive and potentially dangerous.

"It's between two operations; one is where they drill a hole through my temple, and they clip it for good, or the other option is they can thread a wire through my groin, and they clamp it, which they will have to do every so often."

"The neurosurgeon I saw was confident he could do a good job, but there is always that risk (but) the last thing I want is to be paralysed or something and to be a burden on anyone.”

Although John couldn’t step into the ring on the biggest night of his bigger brother’s career, he still made it to Joseph’s corner in Cardiff.

He revealed how difficult it had been to tell ‘big-bro’ about the aneurysm and that he wouldn’t be able to support the undercard.

"Everything was fine when they told me I had it. But as soon as Joe called me he said 'Uce, you all right?"

“I felt overwhelmed. I was starting to get teary, and said 'Uce, I'm all good. As soon as I heard his voice asking if I was OK, it just became overwhelming."

John will once again take his position in Joseph’s corner when he challenges another former Anthony Joshua victim in Dillian Whyte tonight. He is unwavering in his belief that Whyte is in for a tough night, boldly predicting a knock-out within three round in favour of his charge.

On Joseph’s training camp, John said: "At training I've never seen him sharper. He’s hitting hard, he's hitting fast, and he's not just throwing three or four, he's throwing sixes and sevens. His combinations are outstanding, and he's showing good angles, good movement, and his head movement is real good."