David Allen says he owes an apology to former manager Dennis Hobson for not making the most of opportunities presented to him earlier in his career.
The Conisbrough heavyweight was tipped for big things after turning professional at the age of 20 under the guidance of Sheffield promoter Hobson.
But progress was slow for Allen who admits he never gave 100 per cent to the sport in the past.
Allen has adopted a fresh attitude over the last few months, dropping more than three and a half stone to get into the best fighting shape of his career alongside Stefy Bull.
And he feels he needs to apologise to those who invested in him in the past.
“I’m only young but I’ve had a lot of opportunities,” Allen said.
“Dennis Hobson gave me a lot of opportunities and I didn’t take them.
“I apologise to Dennis Hobson for how it turned out.
“In hindsight, I didn’t give it 100 per cent.”
Allen edged to a win over French heavyweight champion Fabrice Aurieng last month in Sheffield in his second fight since joining up with Bull.
There was a sense of disappointment in the performance, based mainly on the heights Allen reached during his training camp for the fight.
But with fitness becoming less of an issue for the 6ft3 fighter, honing his technique will be the priority for future fights.
He said: “In the time that I had for the Aurieng fight I gave 100 per cent.
“I can really box but there’s still a lot more to come from me.
“I’m only 23. I had ten amateur fights and I’ve had nine professional fights.
“I’m a really exciting fighter and I’m determined to put Doncaster on the map like Jamie McDonnell has done.
“Whatever comes next, I’ll be ready. It’ll be another six rounder and we’ll see what happens.”
Allen is scheduled to fight on November 28 at Doncaster Dome and is aiming to impress to a greater extent than he did against Aurieng.
However he still believes the win over the Frenchman was a notable one.
He said: “It was a very good win. He’s rated a lot higher than me.
“I knocked him down in the first 15 seconds but then I got stuck in a fight with a big tough man. It was pretty level.
“I toughed it out, took some big shots and I got the win which is the main thing. It’ll move me up.
“It’s about learning. I’m just going to get back on it and keep learning.
“It wasn’t impressive. It’s no where near what I can do.
“I’m a bit disappointed with the performance but there’s a lot of positives to take. We move on.”
* Kell Brook is highly unlikely to be fit for until January or February, says his promoter Eddie Hearn.
The Sheffield welterweight world champion has a rib injury.
Hearn said: “I don’t think [Brook] will be ready. I know everyone thought [the injury] was just a move to switch him from [Oct] 24th to the 12th, but honestly, it’s not,” Hearn told iFLtv. “His rib’s still not right and we’re five weeks [out] from Saturday until Dec. 12, so it’s more likely January or February.”