Union Rags, left, would have a perfect record but for a photo-finish loss after a wide trip in the Breeders’ Cup Juvenile. (David J. Phillip/AP)

Thoroughbred racing badly needs a 3-year-old star.

The sport’s popularity — as everybody knows — has been declining for years. Racing gets minimal attention on network television and it has disappeared from most sports pages during most of the year.

And yet one part of the game remains remarkably strong: the Triple Crown series. The Kentucky Derby, Preakness and Belmont Stakes still attract huge crowds and widespread media coverage. They can stir the interest of the public at large — particularly when a charismatic horse such as Rachel Alexandra, Funny Cide or Smarty Jones is involved in the competition.

Will there be such a horse in 2012? Racing fans will be scrutinizing the key prep races over the next three weekends looking for Derby candidates, but it is by no means certain that any worthy 3-year-old will emerge.

There was no star in the 2011 Triple Crown series, which turned out to be one of the weakest in decades. The three races were all dismayingly slow, and none of the winners — Animal Kingdom, Shackleford and Ruler on Ice — went on to capture another stakes of consequence. The 2010 series, with the Kentucky Derby won by the forgettable Super Saver, wasn’t much better. If the public and the media start to believe that the Triple Crown races are not great and meaningful events, and are not worthy of attention, the sport will be in even deeper trouble.

That’s why lovers of racing will be rooting for a horse — any horse — to excel in the important prep races that will be contested over the next weekends, beginning with Saturday’s Florida Derby at Gulfstream Park. The $1 million race pits Union Rags — the top-rated colt on most lists of Kentucky Derby candidates — vs. the formidable El Padrino.

Union Rags would have a perfect record but for a photo-finish loss after a wide trip in the Breeders’ Cup Juvenile — a result that cost him the 2-year-old championship. He came back to win his 3-year-old debut in impressive fashion at Gulfstream. But as a speed handicapper I have to harbor reservations about Union Rags. His best Beyer Speed Figure to date is 95 — a level of performance that wouldn’t make him a Kentucky Derby contender even in a dismal year like 2011. El Padrino — the best of Todd Pletcher’s many good 3-year-olds — has finished strongly to win his two starts this year with figures of 100 and 98.

Perhaps this is wishful thinking, but I expect Union Rags to advance to a new level Saturday. Trainer Michael Matz doesn’t ask his horses to deliver too much too soon; he proved with Barbaro in 2006 that he knows how to prepare a horse to produce a maximum effort in the Derby. When Union Rags captured the Fountain of Youth Stakes at Gulfstream last month, he looked as if he had plenty left in the tank. Despite his modest speed figures, he has the potential to stamp himself as a genuinely top-class horse.

Another crucial prep-race confrontation will occur April 7 in the Santa Anita Derby, when Creative Cause has a rematch with Bodemeister. The 3-year-olds in California appear to be a deeper, more talented group than their counterparts in the East, and Creative Cause ran a strong race — earning a speed figure of 102 — to beat Bodemeister by three-quarters of a length in the San Felipe Stakes last month. Creative Cause had the advantage of being a seasoned competitor — he finished a close third in the Breeders’ Cup Juvenile last fall — while Bodemeister was making only his third career start and his first in a stakes. With triple-digit speed figures in two of his three starts, Bodemeister is obviously a prodigy, and he is in the hands of the most astute trainer of Derby horses, Bob Baffert. The key question about him — in next Saturday’s race and in the Triple Crown— is how much his lack of experience will handicap him.

Some of the other colts on most top-10 lists of Derby contenders don’t have persuasive credentials. Hansen, the champion of the generation as a 2-year-old, has never looked like a colt capable of going 11 / 4 miles effectively. Nor does the Baffert-trained Secret Circle, winner in five of his six starts, appear able to handle the Derby distance. I don’t understand the widespread enthusiasm for Alpha (with a career-best figure of 91), though he’ll get another chance to prove himself in the April 7 Wood Memorial at Aqueduct.

It is impossible to anticipate what might happen in the final round of prep races. In the modern era, most young horses are so lightly raced that they have great room to improve in the month before the Kentucky Derby. Horses such as Charismatic (1999), War Emblem (2002) and Funny Cide (2003)were lightly regarded or totally ignored before delivering a strong performance in April; all won the Derby and went on to greater glory. A colt who is now virtually unknown could still turn out to be the racing star of 2012.

For Andrew Beyer’s previous columns go to washingtonpost.com/beyer.