Joel Rosario, who rode General a Rod to a victory in the Gulfstream Park Derby on January 1, will be back aboard the three-year-old in the $1 million Florida Derby on March 29, trainer Mike Maker confirmed on Friday.

The Roman Ruler colt had been ridden by Javier Castellano, who opted for unbeaten Constitution in the Florida Derby. Rosario is third with $2,265,054 in purse earnings and fourth with 46 wins from 309 mounts at the current Champions meet, including a victory aboard Lea in the Grade 1 Donn Handicap on February 9.

"He's not a complicated horse to ride and Joel has won on him before, so we're happy to have him," Maker said. "We've had a lot of success together in the past, and I hope it continues. He's a top-class rider, and I'm glad we've got him."

Maker said General a Rod will breeze again on Saturday morning at Gulfstream with regular exercise rider Joel Barrientos aboard.

"The horse is doing great, and he looks fabulous," Maker said.

Spot, the upset winner of the Grade 2 Swale Stakes at seven furlongs March 1, posted a half-mile move in :47 3/5 Thursday morning at Palm Meadows and remains a possible candidate for the Florida Derby.

"He actually went a little too fast for me," trainer Nick Zito said after the work. "But he did it on his own, and he worked with Grand Arrival, who at one time was a horse with a lot of potential. The horse is doing great. I'll speak to (owner) Mr. (Joe) Moss and we will make a decision after his next work, which will be on March 22."

By Pulpit, Spot was purchased privately by owner Joe Moss following a fifth-place finish behind Wildcat Red in the Grade 3 Hutcheson on February 1 and turned over to Zito. Sent off at 9-1 in the Swale, the uniquely marked gelding reeled in odds-on No Nay Never in the stretch run.

Zito is tied with John Veitch for the most Florida Derby winners, sending out Dialed In (2011), Ice Box (2010) and High Fly (2005), and the Hall of Fame trainer acknowledged that Gulfstream's marquee event is coming up as a loaded affair.

"The Florida Derby is going to be a tough race, no question about it," Zito said. "You've got the Holy Bull winner, the Fountain of Youth winner and the (Todd) Pletcher gang -- those are real horses. One thing about us is that we never say never. If he continues training well, then it's a possibility he'll be in the entries."

Cairo Prince, off since his impressive victory in the Grade 2 Holy Bull on January 25, is expected to be the Florida Derby favorite, while Wildcat Red and General a Rod, the one-two finishers in the Grade 2 Fountain of Youth, are also targeting the $1-million contest along with the unbeaten Constitution, who will make his stakes debut.