The great fear in heavyweight boxing is that David Haye turns out to not be what people hope he is. Or, putting the boxing boot on the other foot, that two-time WBA champion John Ruiz does turn out to be what they fear he is.

No one fears the 38-year-old former champion in the way they feared Mike Tyson or Evander Holyfield. Not like they did an aging and well-faded but still dangerous Joe Louis or Muhammad Ali. They don’t so much fear what he can do to an opponent as they fear what he can make an opponent do to himself. While that is a form of fear, it’s not a terribly marketable form of it.

Stylistically awkward, tougher to negotiate than 20 miles of detours and armed with a chin that refuses to turn on him (or turn his lights out), Ruiz is what heavyweight boxing doesn’t need at the moment. He’s a problem.

Through various maneuverings, legal threats and sheer perseverance, Ruiz has survived nearly 20 years as a professional prize fighter and Saturday will try to use all he has learned while wending his way to two tours as WBA champion to undress, frustrate and ultimately defeat the young British champion David Haye, who is everything Ruiz is not.

Ruiz’s nickname is “The Quiet Man.’’ The bellicose David Haye will never be called “The Quiet Man.’’  He is not a big puncher. Haye has 19 KOs among his 22 victories. He is not a particularly striking physical specimen. Haye looks like Holyfield on steroids.  (Aside: Is that an oxymoron? Just asking.)

But for all that Ruiz is not there are several things he is and that is why HBO never wanted to stage a heavyweight tournament while he was a belt holder and why everyone with a stake in heavyweight boxing is petrified about what could happen Saturday night at MEN Arena in Manchester, England.

Ruiz is dogged. He is also tough in an old-fashioned way. He is willing to absorb punishment to wear you down. He is, according to Holyfield, far stronger than outsiders understand and punches harder than you might imagine. Hasim Rahman found that out with one body shot and refused to let his hands go the rest of the night, losing a fight the world concluded he would easily win.

Incredibly, he’s also one victory away from joining Ali and Holyfield as three-time heavyweight champions. Did you ever think there would be a reason to put those three names in the same sentence when the subject was heavyweight boxing champions? The latter is a measure of Haye’s problem. Ruiz will not go quietly into that good night of fistic retirement. No one can quite believe he’s still around but the fact is he’s had more heavyweight title fights than Jack Dempsey or Rocky Marciano, has not been close to being stopped since the night David Tua caught him with an unexpected punch seconds into their match and laid him low and has learned both how to avoid taking dangerous risks while wearing down an opponent until he becomes mentally sapped and simply concedes winning isn’t worth the trouble.

Truth be told, that short night with Tua was the spawning ground for the stab-and-grab style that made Ruiz a two-time champion but also the enemy of fight fans and cable television executives because of its unpleasant viewing experience. Yet for all his stylistic disappointments, Ruiz fights in the way that works for him and most of the time he imposes that style on his opponents, forcing them to engage in a wrestling match most of them can’t win rather than a boxing match he can’t win. That is a skill in itself, although neither a pleasing one nor one that is much appreciated these days.

Case in point was that Ruiz could easily have been given the victory against Nikolai Valuev to make him a three-time champion when they squared off in Germany several years ago because while he didn’t do a lot he did more than the giant from Russian. That night the highly partisan German crowd in Berlin booed the announcement that Valuev had been given that decision and rightfully so. Ruiz won the fight. He just didn’t get the win.

None of that means he can beat Haye, who is younger, faster of hand and foot, more powerful and cocksure of himself. Many boxing experts, including the great trainer Freddie Roach, are urging him to come out and attack Ruiz from the opening bell, looking to stun him early  and take him out in the kind of spectacular way that would create a big-money unification fight with one of the Klitschko brothers.

The Klitschkos presently hold three of the four major belts, with Haye having snared the WBA title from Valuev in a lackluster performance in which he was unexpectedly docile but he is still widely seen as the man most likely to pump life back into the long dormant heavyweight division.

He failed to do it against Valuev, staying on the outside and landing his jab and then tying up the bigger but ponderously slower Valuev in a safety first approach Ruiz would have been proud to call his own because it tied Valuev in knots while also tying a title belt around Haye’s waist, which in the end is still the first goal of boxing.

But if Haye tries a similar approach against Ruiz he will be booed out of the arena and may find himself enveloped in a cocoon of horror, as Peter McNeely might put it. Then again, attack Ruiz too wildly and he may get countered the way Holyfield did when Ruiz dropped him for one of the few times in Holyfield’s career or the way he stunned Rahman and Kirk Johnson, basically convincing both it was easier to submit and quit fighting than risk repeating the pain of what they’d felt.

If Ruiz’s hand is raised it is not 100 per cent sure than even his promoter,  Oscar De La Hoya, will be thrilled about it because De La Hoya, in the best tradition of Don King, also has the American promotional rights to Haye. You don’t have to be P.T. Barnum to know which of the two is more promotable.

In a sense, De La Hoya’s Golden Boy Promotions wins no matter which fighter does but it wins big if Haye looks spectacular. It wins control of the WBA title if Ruiz wins but what then? The Klitschkos want no part of the problems he represents, they being more interested in risk reward ratios than most insurance companies. That is especially true of young Wladimir, who is easily daunted by someone who would fight him like a heavy drapery, as Ruiz would.

So while there are many things to be unsure of about Saturday night’s Haye-Ruiz heavyweight duel one thing is as clear as a bell. If when the last one sounds they raise the hand of John Ruiz and name him heavyweight champion for the third time a lot of people in boxing will have seen their worst fears materialize…for the third time.