By sunset on Saturday, the Union Rags story will include another important chapter.

If this colt, trained by Michael Matz of Barbaro fame and owned by Chadds Ford's Phyllis Wyeth, wins the $1 million Florida Derby impressively, Union Rags won't just be the Kentucky Derby favorite - he already has that claim - but the buzz will grow that maybe this is the year for a Triple Crown horse.

It might seem unfair, even crazy, to put that kind of label on a 3-year-old, given the difficulties of the Triple Crown path, but it's a common early-spring fever, and Union Rags picks up believers with every stride, including during workouts.

He is the 6-5 morning-line favorite for his last Kentucky Derby prep Saturday, leaving from Gate No. 6 at Gulfstream Park in Hallandale Beach, Fla.

When Union Rags was a 2-year-old, a common observation was how the horse looked like a 3-year-old, which brought up the question: Was he an early developer or would he keep progressing? Matz believes that significant progression has continued.

"He matured physically and mentally . . . [that] is what we're looking at right now," Matz said this week on a national conference call. "We're just looking at a bigger, stronger - a more mature horse."

Union Rags' only career defeat was in the Breeders Cup Juvenile last November when he lost by a head to Hansen. But Union Rags had a wide trip all the way around and drifted in the lane. His trip was calculated to be almost nine lengths longer than the winner.

In his only start this year, Union Rags had a perfect trip and romped impressively in the Fountain of Youth at Gulfstream, winning by four lengths under Julien Leparoux. For the Florida Derby, the competition steps up, led by El Padrino, the Todd Pletcher-trained winner of the Risen Star Stakes, and the 2-1 second choice.

Another big Derby prep, the Louisiana Derby, goes off Sunday at the Fair Grounds in New Orleans. The favorite there is another colt with local connections. Mark Valeski, trained by Delaware Park-based Larry Jones, is coupled with another Jones entry, Mr. Bowling, as a 2-1 favorite in a 14-horse field.

But more eyes are on Florida and Union Rags. Barbaro won the Florida Derby and the Kentucky Derby before breaking down in the Preakness. Matz was the newcomer to the classic races then. Now, he knows the landscape.

Asked if there is anything specific he is worried about right now, Matz said, "You're always worried about the same thing that can happen at the Breeder's Cup," referring to the tough trip, "but he has trained very well coming into the race.

"We set a schedule for him the beginning of the year and we've been able to follow that, and our main goal is to get to Kentucky Derby and May, and so far, everything has gone as we had planned to reach that goal at this point. "

Matz added: "He's trained well. I mean, if he gets beat by a, you know, a better horse, then he [does], but he has done everything we've asked him to do. I wouldn't trade places with anybody right now. . . . Knock on wood, so far it's been straight down the line what we've planned."

Contact Mike Jensen at 215-854-4489 or or follow on Twitter @Jensenoffcampus.