We remember all of the following images with an unfortunate cringe. They famously represent the perils of holding out hope.

• Johnny Unitas tossing interceptions in a Chargers uniform.
• Willie Mays flubbing fly balls for the Mets.
• Emmitt Smith, in Cardinals red, stacked up at the line.

All painful examples, they hit us where it hurts most - right in the soft spot we have for our sports legends.

Mixed martial arts is clenching for a blow to that area. If it's delivered, on some level it could be even more excruciating than the others, given that brutal knockouts produce more unsettling reactions and hold more finality than wobbly interceptions or base-path stumbles.

It would be a shame to see Chuck Liddell put flat on the canvas again - the picture he left us with on Sept. 6, 2008. That's when "The Iceman" was cold-cocked by Rashad Evans.

It was difficult to take in, considering the number of times Liddell had crumpled foes in the same manner over the years. He almost made knockouts appear easy.

Now comes the hard part.

Liddell is 39 years old and participates in a sport that's getting deeper by the day. He became the face of MMA (and the most recognizable stud to wear a Mohawk since Mr. T) with an awesome string of wins during MMA's boom. That formed the bedrock of his lore.

So, we should hope Liddell finds the answer to a perplexing question that every superstar faces as erosion begins.

When to quit?

Liddell seems unwilling to acknowledge the question. He has talked recently of getting "his" belt back, as if his devastating power will keep him in the UFC's light heavyweight title conversation despite the rise of Evans, Lyoto Machida and Griffin, and the continued excellence of Quinton Jackson.

It shouldn't. Over the last two years and four fights, Liddell's only win was a decision in a slugfest against Wanderlei Silva that rekindled fans' hope. Then, Evans brought out the extinguisher that clouded Liddell's future.

This much we know: The former champion has at least one more fight. On Saturday at UFC 97, Liddell faces Mauricio "Shogun" Rua, a man on a different kind of descent.

If Liddell loses, or even pulls out a dull win, UFC President Dana White is likely to interrupt his desire for the spotlight and lust for victories with some common sense. He might not let his friend fight again.

Rua seems like a fool's gold-type of opponent for Liddell. In two UFC appearances after dominating in Japan, "Shogun" was choked out by Forrest Griffin then needed each of his unimpressive strikes and heavy breaths to defeat an old Mark Coleman.

The UFC-version Rua isn't a representative of top-tier 205-pounders, making it hard to imagine a result that would stir talk of Liddell's resurgence.

Not with so much simmering talent at light heavyweight, and not with the young bucks at the next weight up, either.

Just last year, the UFC's heavyweight division was thought of as bereft, perhaps a place where someone like Liddell could start fresh even at his age. Now, it looks like a breeding ground for huge, scary prospects.

So, excuse me if I'd rather not see a slightly larger Liddell trying to fend off freakish up-and-comers who would welcome the chance to put his head on their mantel.

Instead, here's hoping Liddell finishes on a high note...