Casse Duo Nitrogen, Nerazurri Fire Perfect Works for Apple Blossom

Eight days from the $1.25 million Apple Blossom Handicap, the most important health report in Mark Casse's barn is not a vet's note. It's a stopwatch.

Nitrogen and stablemate Nerazurri each breezed five furlongs at Oaklawn Park on Wednesday morning, and assistant trainer Caden Arthur came away from the track with nothing but confidence heading into the April 11 Grade I target.

"It was perfect," Arthur said. "Both of them looked great. Very happy with them. Nitrogen had a little stronger work last week, so we didn't ask too much from her this week. Both of them did it very easy, in hand. I think Nitrogen, she likes this fast track."

The splits backed him up. Nitrogen, the reigning Eclipse Award champion as North America's best 3-year-old filly of 2025, covered five furlongs in 1:01 flat with opening fractions of :25.20 and :37.60, then galloped out an additional furlong in 1:13.60. That kind of composed, maintenance-style move is the signature of a camp that already did its heavy lifting and is now managing fitness. Nerazurri worked alongside her in company under regular rider Cristian Torres, clocking 1:01.20 for the identical trip.

The context makes both times more meaningful. Nitrogen arrives at the Apple Blossom with unfinished business in high-stakes company. A daughter of Medaglia d'Oro owned by DJ Stable LLC and trained by Hall of Famer Casse, she rattled off six stakes wins in 2025, headlined by the Alabama (G1) at Saratoga, and ran second in last year's Breeders' Cup Distaff. The Apple Blossom carries "Win and You're In" status for this autumn's Breeders' Cup Distaff at Keeneland, making it effectively a semifinal for the sport's elite fillies and mares. Her most recent start, a third-place finish in the $400,000 Azeri Stakes (G2) on March 7, represented an off trip on a track that Wednesday's work suggests suits her considerably better. Never off the board in 13 career starts before that run, Nitrogen now shows more than $2.1 million in earnings. Wednesday's controlled five-furlong move on a fast strip reads as a confirmation, not a preparation.

Nerazurri brings a contrasting profile. A wire-to-wire type by Protonico owned by Michael Eiserman, she went gate-to-wire to take the inaugural $135,000 Oaklawn Sports Overnight Stakes on New Year's Day, then ran second to Nitrogen in the G3 Bayakoa in February before adding another Oaklawn overnight stakes win. She has five victories from 15 career starts and has not yet beaten Nitrogen in graded company, but she makes pace, and pace is leverage. If Nerazurri goes to the front in a field that includes Azeri winner Majestic Oops, she scrambles the tactical picture for every stalker behind her, including her own stablemate.

That is the Apple Blossom shape Oaklawn fans should anticipate: a confirmed front-runner against an Eclipse Award winner still capable of big things on the right track, with a Breeders' Cup Distaff berth as the prize. Casse is fielding both sides of that equation, and Wednesday's parallel works confirm he has both of them pointed exactly where he wants them.