David Haye edgy but Tony Bellew must be perfect to win in London

BBC Radio 5 live's boxing podcast focuses on Amir Khan, Tony Bellew, David Haye and Manny Pacquiao

David Haye has rarely been one to conform.

Before commentating on his first world-title success in November 2007, I remember wandering into the lobby of the hotel in Paris where we were both staying to see Haye lounging around, talking to friends.

It was late Saturday afternoon and the biggest occasion of his career at that stage - against the Frenchman Jean-Marc Mormeck - was just hours away.

Frank (now Kellie) Maloney, his then promoter, was concerned about Haye's attitude. "I wish he would just go to his room and relax," Frank said to me.

Rest and solitude might have been prescribed for most boxers but Haye never read the copybook.

• Listen to Costello and Bunce on 5 live's boxing podcast

In beating Mormeck, a man who had lost only once in the previous decade, Haye produced one of the greatest wins by a British boxer in a foreign ring.

Two years later, he gave away seven stone in weight and made the Russian beanstalk Nikolai Valuev chase shadows in Nuremberg to add a version of the world heavyweight crown to his cruiserweight glories.

Previously, only Evander Holyfield had won world titles in both divisions. And Haye won each of his away from home.

Haye won cruiserweight world titles in 2007, more than eight years before Bellew claimed the WBC strap in the division

Back then, his ability to revile took root. His comments at news conferences and other promotional events were as disgusting as his ringside analysis was erudite. Social media platforms were unborn or in their infancy but still he got his vulgarity across.

Judging by his attitude in the build-up to the Tony Bellew fight this weekend, the persona endures. But in attempting to rattle Bellew, Haye himself has lost at least a semblance of control.

He complained after Monday's news conference in Liverpool about some of the abuse he was subjected to by the hundreds of Bellew fans in attendance. Having promised to "cave someone's skull in", there was little room for objection when the fire was returned.

A sub-plot on Saturday is the daunting challenge facing the trainers, both of whom are coming off defeat in a world title fight. Shane McGuigan was in the corner when Carl Frampton was beaten by Leo Santa Cruz in their rematch in January. Dave Coldwell has suffered reverses with Gavin McDonnell and heavyweight David Price in a three-week spell.

The careers of McGuigan and Coldwell will continue after Haye and Bellew have departed the scene but the result on Saturday will help shape how they are regarded.

Part of the trainers' role will be to moderate emotions and limit the red-mist tendencies. But whatever the guidance from the corner, the most important factor relates to how much of Haye the fighter, the calculated practitioner who beat Mormeck and Valuev, remains.

Haye's trainer Shane McGuigan (left) and Bellew's coach Dave Coldwell have both recently tasted defeat

In almost five years, Haye has been involved in only two fights, against non-league opposition, lasting a total of less than seven minutes. In the same period, Bellew's log shows 13 fights and 113 rounds.

For all that, the fight has the feel of last year's showdown in Las Vegas between Amir Khan and the Mexican Saul 'Canelo' Alvarez, when Khan was knocked out savagely in the sixth round.

We tried to make a case for the underdog but the evidence against him was overwhelming. And Bellew is quoted at even longer odds than Khan was back then.

McGuigan has indicated that Haye might weigh in lighter than Bellew, suggesting an attempt to rekindle the blazes of old. The adage tells us that the last asset a fighter loses is the power of his punch. Perhaps… but he does lose the ability to land it.

Even so, Haye only has to get it right once. Bellew must get it right all night.

Not the low-key event Khan promised

Momentum is building around a showdown between Khan and WBO world welterweight champion Manny Pacquiao. Khan was BBC Radio 5 live's big fight summariser alongside me in Vegas recently when Frampton was outpointed by Santa Cruz.

That night, Khan was adamant that his next fight would be a relatively low-key affair because he wanted to test the right hand on which he had surgery after the Alvarez defeat last May.

The location of Khan's 23 April meeting with Pacquiao is yet to be confirmed

But the money and the prestige of a showdown against Pacquiao make an offer difficult to refuse. I watched them train together in making a documentary about Pacquiao for BBC World Service in 2010. At the time, the Filipino was preparing for a light-middleweight title fight against Mexican Antonio Margarito and Khan was among the sparring partners.

Pacquiao beat Margarito emphatically and Khan went on to outpoint Argentina's Marcos Maidana in Vegas shortly afterwards for one of the most impressive victories of his career.

More recently, Pacquiao has recovered from his defeat against Floyd Mayweather almost two years ago to beat Americans Timothy Bradley and Jessie Vargas. At 38, he might well be fading but Pacquiao is still better than most. And those performances since May 2015 serve to endorse the greatness of Mayweather.

The critics continue to carp about Mayweather's credentials and a record supposedly padded with carefully-chosen fall-guys. Yet consider what Puerto Rico's Miguel Cotto, Mexican Juan Manuel Marquez and Pacquiao have gone on to achieve after losing to him and the arguments descend into nonsense.

Fighting talk is decades in the making

Costello and Bunce graced a venue called The Cat's Whiskers as teenage fighters long before teaming up for 5 live

We launched a new "5 Live Boxing" podcast this week, with me and long-time ally Steve Bunce in union. It is 42 years this week since we first appeared together on a junior club show in Streatham, south-east London, at a boxing hotbed called The Cat's Whiskers.

We both lost but a lifelong passion was being battered into us. Also on the bill was Sammy Reeson, who 10 years later became the first holder of the British title in the new cruiserweight division.

Among my future opponents was Jim McDonnell, who later took the legendary Ghanaian Azumah Nelson into the 12th round of a world title fight and now trains the British world super-middleweight champion James DeGale. Jim beat me on points and never granted me a rematch. Strangely, I never complained.