Klitschko, who was born in 1976 in Kazakhstan and is nicknamed "Dr. Steelhammer," is the current holder of the International Boxing Federation (IBF) title. He is considered the favorite against Ibragimov due to the advantages of having a longer reach and being so tall (1.99 meters or 6 feet 7 inches).
Klitschko's older brother, Vitaly, is also a former heavyweight champion who ran as a mayoral candidate in Kyiv in 1996, finishing second.
Ibragimov, who was born to ethnic-Tatar parents in Daghestan in 1975, is the current World Boxing Organization (WBO) champion. He's much shorter than Klitschko, standing 1.88 meters (6 feet 2 inches).
Ibragimov has never lost -- winning all 22 of his fights, 17 of them by knockout. Klitschko has a record of 49 wins and three losses, with 44 knockouts.
Klitschko is a multimillionaire and has a Ph.D. in sports science. He lives in a mansion in Beverly Hills and speaks fluent English.
Ibragimov's English is heavily accented and rather basic. He hasn't made the big money yet and trains behind an auto-repair shop in Florida.
Gagic Khachaturyan, a former boxing champion from Armenia who lives in Hamburg, Germany, knows both contestants and, like many others, thinks Ibragimov is the underdog.
"Ibragimov is a very smart fighter. He's a problematic opponent," Khachaturyan says. "I spoke with Ruslan [Chagaev], and he said that Klitschko will not have an easy fight. I think this fight will not be decided by a technical score but by a knockout. Maybe a quick one. Klitschko learned a great deal from his [three] losses [knockouts]. He wised up, he became stronger in character. His jaw is a weak point, in my opinion, and if Ibragimov manages to punch him there -- then maybe [he could win]. But I don't think so, his power punch is not that strong. He's got a chance only if he knocks out Vova [Klitschko]."
Just a decade ago, in a sport heavily dominated by African-Americans, it was unthinkable to imagine that all the top spots would one day belong to a cohort of fighters reared in the Soviet Union.
Their emergence on the world stage has coincided with the gradual decline of the great American heavyweight boxing tradition that produced such household names as Joe Louis, Muhammad Ali, George Foreman, Evander Holyfield, and even the controversial Mike Tyson.
Tim Smith, a boxing columnist for the "New York Daily News," attributes the rise of the CIS fighters to the political and social changes that have taken place in the former communist states during the last two decades.
He says that although the American dream of becoming rich and famous is not alien to any of the top contenders, their early years within the Soviet sport system have made them focused and motivated.
"I think they're very, very focused," Smith says. "And I think that might have come from the discipline of the system, the sport system that they came out of. I talked to Klitschko down in Florida, [and he told me that] he found the former Soviet sports academies to be very oppressive. What he did find, [though,] is that it made him mentally tougher. And it made him very focused. It made him concentrated on being properly trained and being disciplined. And those are the kinds of things when you are kid, when you're growing up, those are the kinds of things that you carry over into your adult life. We're seeing that fighters from those Soviet bloc nations are coming with that kind of discipline and that kind of focus."
Smith says that it wouldn't be proper to see the current trend only as "white guys replacing black guys" at the top because such things in boxing go in cycles.
Khachaturyan, the former Armenian boxer, echoes Smith's observations by saying that poor management skills, incompetence in the pro-boxing field, and the lack of proper training facilities are swaying talented boxers from Eastern Europe to look for opportunities elsewhere.
"Our guys can now travel freely," Khachaturyan says. "They can sign contracts to earn more money. You can see it. Whoever's got the potential in Russia, they want out -- to Germany, England, the U.S. -- to get better contracts. In Russia, they are poorly paid. I know good boxers there. They've got the potential but don't have a [good] manager, no sponsor."
Khachaturyan says that if a boxer is being paid $10,000 for a fight in Russia, he could easily make $150,000 for the same fight in Germany.
Germany is the adopted country of the Klitschko brothers and although they remain extremely popular there, in 2004 the brothers moved to California. Ibragimov has been training in Florida since 2003.
The absence of big American fighters from the field has negatively affected the commercial aspects of the sport.
In Mike Tyson's heyday in the late 1980s and early 1990s, for example, he could get guaranteed prize money of up to $30 million per fight. The prize money for this weekend's bout is nowhere near that level.
Speaking to RFE/RL after a recent workout, Ibragimov said he wishes Klitschko "good luck" and hopes that he recovers quickly after their fight on February 23.
All joking aside, Ibragimov says he believes it's important to get closer to having one single heavyweight champion instead of the four that currently exist.
"Of course, this bout is important. It is important in the sense that it is the 'unification' fight," Ibragimov says. "I've fought for championship titles but never a unification one, so it is very important for me. We must do whatever we have to do to unify the competing titles into a single one."
The fight is the first heavyweight unification bout since 1999, when Britain's Lennox Lewis emerged as the undisputed champion by defeating Holyfield.
If Klitschko defeats Ibragimov, his mandatory challenger will be -- that's right, another Russian: 28-year-old Aleksandr Povetkin. Povetkin is seen as one of the "youngbloods" in boxing's heavyweight division and is considered a leading contender.