HOT SPRINGS, Ark. – Nitrogen breathes different air as a champion, and trainer Mark Casse is hoping her class will help her overcome a disrupted training schedule when she launches her 4-year-old season Saturday in the Grade 3, $250,000 Bayakoa at Oaklawn Park. The 1 1/16-mile race for fillies and mares is the first stepping-stone toward the Grade 1, $1.25 million Apple Blossom Handicap here April 11. Nitrogen won the Eclipse Award as North America’s outstanding 3-year-old filly of 2025. The Bayakoa will be her first start since she finished second in the Breeders’ Cup Distaff on Nov. 1 at Del Mar. Nitrogen was freshened after the Distaff and has since posted works in Florida and Arkansas. Among her drills was five-eighths in 1:00 on Jan. 17, the fastest move of 62 at the distance that morning at Oaklawn. A winter storm system closed the track for training from Jan. 24-Feb. 1. “She’s the one that concerns me the most with the track shut down because unlike the rest, she’s coming off a layoff, getting ready,” Casse said of his starters this weekend at Oaklawn. “Her work, where she had the bullet Jan. 17, it was really good. I thought she finished good. She galloped out strong. She hardly took a deep breath. That’s why we’re in. “If I didn’t say that I was a little concerned, because obviously things have not went perfect, I’d be lying. But she’s a different horse than most. I’m going to rely on her ability. She’s not at her very best, but her 90 percent is extremely good. So I’m going to rely on her class here.” :: Live racing action at Oaklawn Park! DRF Past Performances and Picks are available now. Nitrogen is a daughter of Medaglia d’Oro who races for her breeders, D. J. Stable. The $2 million earner won six stakes races last year, led by the Grade 1 Alabama, and was second in three others, including the Spinster in her first start against older runners Oct. 5 at Keeneland. “She could have easily been eight out of nine,” Casse said. “She got beat a tough one in the race won by Fionn on the turf [the Belmont Oaks], and then her Spinster race was really good. So, going into the Breeders’ Cup, she was less than a foot from being undefeated last year.” In the BC Distaff, Nitrogen rallied to finish 5 1/2 lengths to Scylla. She earned a Beyer Speed Figure of 95, which equaled her best career number and ranks as the best last-race Beyer in the Bayakoa. “About mid-summer, I started thinking she could be champion 3-year-old filly,” Casse said. “I didn’t think anybody would beat Good Cheer, but Good Cheer kind of stubbed her toe a little bit and so then everything I did after her winning the Wonder Again, my goal was to try to make her champion 3-year-old filly. Everything I did from that point on was with that goal in mind.” Nitrogen is part of a seven-horse field Saturday that includes Quietside, winner of last year’s Grade 2 Fantasy and Grade 3 Honeybee at Oaklawn. The John Ortiz-trained millionaire is making her first start since running second in the Grade 3 Comely on Dec. 7 at Aqueduct. Casse also will start Nerazurri, who breaks from the rail after winning both of her starts this season at Oaklawn. “She’s gotten good,” he said. “She’s got some speed, got a good post. She’s sharp.” Nitrogen will start from post 7 under regular rider Jose Ortiz. “One of the things that makes her great is she can do whatever Jose wants her to do,” Casse said. Sandman returns to races Sandman, who won last year’s Grade 1 Arkansas Derby, makes his first start since August in Saturday’s fourth race. The 1 1/16-mile conditioned allowance, which carries a $100,000 claiming option, also drew Grade 2 winner Catching Freedom and Fair Grounds shipper San Siro. Sandman leads the nine-horse field in earnings with $1.5 million. He will start from the rail under Ortiz. “We’ve got Sandman back, so that’s exciting,” Casse said. “We’d given him a break. He’s grown up. This is just the beginning of hopefully a big year. He’s ready. Is he 100 percent? Probably not, but he needs to run.” The race could serve as Sandman’s springboard to the Razorback Handicap at Oaklawn. Catching Freedom won the Smarty Jones at Oaklawn in 2024, the same year he captured the Louisiana Derby before running a big fourth in the Kentucky Derby. Francisco Arrieta has the mount for trainer Brad Cox. San Siro is moving back into the overnight ranks after seven straight stakes starts. Cristian Torres has the mount from post 2 for trainer Brendan Walsh. :: Want to learn more about handicapping and wagering? Check out DRF's Handicapping 101 and Wagering 101 pages.