Wladimir Klitschko can’t win Saturday night in Hamburg, even if he wins.

If the alleged best heavyweight in the world easily defeats challenger Tony Thompson, the world will say “Who?’’ and dismiss the victory as nothing more than a televised sparring session. If he doesn’t, they’ll say he was never who he claimed to be.

And if God forbid he loses to the 36-year-old American unknown, the world would again say “Who?”… but they’d now be referring to Klitschko.

That is the dilemma the IBF-WBO champion must deal with. If he struggles to find ways to assault the 6-foot-5 southpaw, he will be sternly criticized. If he doesn’t, the victory will be dismissed as having come at the expense of an unfit opponent. And if Thompson makes good on his threat to upset Klitschko, the champion will be seen as a figment of HBO’s imagination.

Regardless of how it goes then, after this fight Klitschko will begin to understand that in theory it is a noble cause to try and unify the heavyweight title but in practice it is a headache because it saddles you with mandatory defenses like this one, and another that is pending against Russian Alexander Povetkin, that earn you nothing but a few more dollars.

Once there was a time when boxers fought their way to the top but today their advance to No. 1 contender status is more a war of attrition than a war of ascension, with the warfare kept to a minimum along the way if at all possible. What results are fights like this one between a champion and an opponent the average fan has never heard of and couldn’t care less about.

Take Thompson, for example. He began his professional career at the advanced age of 27 and since then he has won 31 of 32 fights, 19 by knockout. His list of victims carries with it few names the average fight fan would recogniz,e let alone the less committed general sports fan.

So how did he get into position to plague Klitschko for at least one night at Color Line Arena? Primarily because the sport has run out of bodies to put in front of the three presently reigning heavyweight belt holders.

That does not mean Thompson can’t fight. It just means if he can, it’s been a well kept secret. When your most important victory was over Luan Krasniqi, the world has no idea who you are. When such a man is then put in front of the heavyweight champion of the world it leaves the champion in a bind.

Destroy such a challenger and it’s said that he wasn’t much of a challenge. Don’t destroy him and it reflects badly on you rather than positively on him. In some parts of the country this would be called a trap. In Klitschko’s house it’s just called a pain.

According to Thompson, this situation exists because for the past 10 years he has had to contend with being avoided by a host of higher ranked heavyweights. Only until they all were beaten by someone else did he get his chance. Well, that’s one way to look at it. The other would be to go back to the original question about Tony Thompson – which was, “Who?’’

Klitschko managed to unify at least a portion of the fractured title in his last outing at the expense of Thompson, who had to step aside from his own overdue shot at then WBO title holder Sultan Ibragimov to provide Klitschko that opportuity. For this kindness, Thompson will be paid more than his reputation would normally allow him to demand for an opportunity to win half the world’s heavyweight titles in one swoop.

Thompson has long been ignored (his handlers claim) because he is a tall left-hander who possesses inordinately long arms, an above average jab and an alarming tendency to win by what he himself has called “effective clumsiness.’’

If you are relying on effective clumsiness to beat Wladimir Klitschko (50-3, 44 KO) you may be banking on the wrong tools, even though they have worked in the past for Thompson, who has not lost a fight since dropping a four-round decision eight years ago in a tent on Cape Cod used primarily for summer theatre.

A failed high school football player, Thompson earned his GED in the Job Corps and was working in D.C. as a sort of tour guide when he discovered boxing at the age of 27 after finding the Round One Gym and a trainer named Tom Browner.

Since his only loss he’s won 27 straight, including victories over former title contender Vaughn Bean at a time when Bean was 44-3, Dominick Guinn and the aforementioned Krasniqi in a WBO title eliminator that ended with the German beaten into submission in less than five rounds in the very same arena where Thompson will square off with Klitschko.

Thompson’s lack of a resume does not mean there is no risk for Klitschko of course. There is always the risk of defeat from a blind punch but the larger risk is that the champion wins but doesn’t look good doing it. Or the reverse.

Either way, Wladimir Klitschko is a man who can’t win Saturday night (afternoon if you’re watching the 4:30 pm HBO feed). If he looks good it’s Thompson’s fault. If he looks bad it’s Klitschko’s fault. Who needs this?

Klitschko does if he wants to retain the WBO belt he now carries to keep his IBF one company. But this is not a fight that will lift his profile or his standing among the world’s fight fans, although it could hurt it even in victory.

“I saw his knockout win in Germany so I definitely won’t underestimate him,’’ Klitschko has said of Thompson. That’s good but the world already probably has, which only serves to further increase the risk he is facing while lowering the reward he will earn in victory.

That is the curse that comes with mandatory title defenses these days because they are most often against opponents the larger public knows nothing about and hence gives you little credit for accepting. Having said that, Thompson himself is brimming with confidence. He has come to Germany to win. Or so he thinks.

“I’ll be incredibly awkward on offense and defense to the point of frustrating him,’’ Thompson has warned. “Once they get frustrated, I take them out.’’

Not exactly. Thompson has only 19 knockouts in 32 professional fights (a concussion rate of barely 59 per cent) while Klitschko has a more than 90 per cent stoppage rate. That is another reason the world expects Klitschko to destroy Thompson, so if he does he gets no credit and if he doesn’t he begins to be looked upon the way Doubting Thomas looked at his fellow disciples – with some skepticism.

Come July 12 a challenger who calls himself “Spare Parts’’ and says he left a broken air conditioner and a broken stove behind at his Washington, D.C. home, will get his moment. If it lasts too long Wladimir Klitschko will be heavily criticized for it. If it doesn’t, the same thing will happen.

That is the dilemma of being a heavyweight champion at a time when the opposition is mostly made up of lightweights.