by David P. Greisman

Sergio Martinez is 39 years old and the lineal middleweight champion. The opponent that fans most want to see him face is Gennady Golovkin, a fellow titleholder at 160 pounds, a power-punching undefeated 31-year-old whose 29 wins include 26 by way of knockout.

Adonis Stevenson is 36 years old and the lineal light heavyweight champion. The opponent that fans most want to see him face is Sergey Kovalev, a fellow titleholder at 175 pounds, a power-punching 30-year-old who is 23-0-1 with 21 knockouts.

In an ideal world, we would see Martinez-Golovkin and Stevenson-Kovalev in 2014 or early 2015. There are few guarantees in life, however, and particularly in boxing — an enterprise in which it can be astonishingly difficult to make a fight between two testosterone-laden men eager to advance their careers by hurting others.

There are always reasons and excuses not to fight. All we can do in response is convey our displeasure, largely verbally, but also by refusing to turn on our televisions or turn up at the arenas.

Martinez vs. Golovkin and Stevenson vs. Kovalev might very well happen soon. But if those fights fail to come to fruition, it will be because of the ironic fact that the fights that we fans demand most are not always the fights that will earn the most money.

Fortunately, these aren’t cases of high risk carrying low reward. Martinez and Stevenson would be paid handsomely for collisions that HBO has been investing in and building toward. Still, what each appears to be doing is seeking to get the most money out of what remaining time he has left at the top.

Martinez is due to return this June for his first fight in more than a year, a layoff spent recovering from injuries that originated in his September 2012 win over Julio Cesar Chavez Jr. and were exacerbated in his April 2013 victory against Martin Murray. Martinez will face Miguel Cotto in a pay-per-view main event.

Cotto, a former titleholder at 140, 147 and 154 pounds, is a smaller fighter, albeit one who will bring Martinez a significant payday on par with his bout with Chavez Jr. Martinez has accepted Cotto’s terms, reportedly including a catch-weight of 159 pounds, Cotto’s name being billed first, and Cotto walking to the ring last. Accepting those terms means Martinez will face Cotto in an event that will take place at New York City’s Madison Square Garden. Cotto has headlined there eight times before. This will be the fifth time that a Cotto fight will be in New York City during the same weekend as the annual Puerto Rican Day Parade.

Though Cotto’s only pro losses have come against Antonio Margarito, Manny Pacquiao, Floyd Mayweather Jr. and Austin Trout — respectively, one good foe, two great fighters, and a skilled, larger opponent — he’s nevertheless thought to be on the tail end of his career. His title reign at junior middleweight wasn’t compelling, beginning with a win over Yuri Foreman and continuing with a pair of successful defenses against Ricardo Mayorga and a damaged Margarito. That run was followed by the losses to Mayweather and Trout.

Cotto did look good with his demolition of the admittedly limited Delvin Rodriguez last October. It remains to be seen whether Cotto, now working under famed trainer Freddie Roach, can compete once again at the highest level.

All of the above, then, makes Cotto a highly desirable dance partner for Martinez’s comeback fight. Martinez is a smallish middleweight, but one who has acclimated to the division and has been successful during his four years there. Martinez’s team didn’t want to jump straight back in against the toughest possible challenge. And so this way, if Martinez has recovered well enough, he will beat Cotto and then can choose to move on toward a Golovkin fight. Yet if Martinez’s body is still failing him, then he will be sent off into retirement with quite the golden parachute.

As for Stevenson, he is expected to defend against Andrzej Fonfara this May in what is expected to be his final keep-busy bout before facing Kovalev later in the year.

Last week, Stevenson announced that he had signed with powerful boxing adviser Al Haymon, a move he believes will bolster his bottom line. What Haymon will mean to the negotiations remains to be seen. Perhaps he will bring more money to the table for Stevenson. Or maybe he will make demands that end up delaying the Kovalev fight. It’s rather useless to get into too much speculation, however, given our lack of knowledge as to what Stevenson and Haymon will ask for.

The window of opportunity is already brief enough for boxers who reach the top at ages younger than Martinez and Stevenson did. Rare are the stars who shine for more than a decade, who captivate crowds and cash in for a prolonged period of time.

Martinez turned pro 16 years ago, though he didn’t make his HBO debut until 2008, when he was 33 years old. He’s been featured by HBO since, with a total of nine network appearances and one pay-per-view main event. Those have been good paydays, but combined are still less than Pacquiao or Mayweather make in one night.

The more money Martinez can make in what might be his final fights, the richer he will be in retirement. That is probably why he pursued a fight with Chavez Jr. instead of other, more skilled but less famous opponents. It is probably why Martinez rushed his recovery and returned to face Murray, performing in front of tens of thousands in Martinez’s native Argentina. And it is why Martinez is facing Cotto first and not Golovkin.

Stevenson went from fighting against lower-tier opponents on ESPN2 and WealthTV in late 2012 and early 2013 to making his HBO debut against then-lineal champion Chad Dawson. That was just last June; Stevenson was 35 at the time. He was 29 when he turned pro. Now he is seeking increased fortune to go along with his increased fame. It’s no surprise, then, that Stevenson has called out Bernard Hopkins on more than one occasion. Hopkins is with Golden Boy Promotions, which works with Showtime and not HBO. It’s uncertain whether Haymon can bridge that divide.

In the end, it all depends on what the fighters want. What we want, of course, is Martinez-Golovkin and Stevenson-Kovalev. We can speak out and speak with our wallets, yet none of that matters if there are more lucrative options available. Sometimes boxers will value the prize over pride; a good risk-reward ratio means both health and wealth.

The good news is that there’s still good money in Martinez facing Golovkin and Stevenson facing Kovalev. There are few guarantees in boxing, but this cliché is often accurate: If it makes dollars, it makes sense.

The 10 Count will return next week.

“Fighting Words” appears every Monday on BoxingScene.com. Pick up a copy of David’s new book, “Fighting Words: The Heart and Heartbreak of Boxing,” at http://bit.ly/fightingwordsamazon or internationally at http://bit.ly/fightingwordsworldwide . Send questions/comments via email at fightingwords1@gmail.com