The veteran trainer will have four starters in the 12-horse field Sunday for the $1-million Queen's Plate at Woodbine Racetrack in his quest to finally win North America's oldest continuously run stakes event.
"I've had a lot of time to think about that since I've never done it," Casse said about what winning the Plate would mean to him. "I've won a lot of big races and been very fortunate but I would put the Queen's Plate at No. 1 if we were able to win it."
Casse has established himself as one of Canada's top horsemen. The 52-year-old American has been named the country's top conditioner five times and earned the Woodbine trainer's title on seven occasions.
But Casse's best Plate finish was second in 2011 with 61-1 longshot Hippolytus. On Sunday, he'll send out Dynamic Sky, the 4-1 early third choice with Joel Rosario, North America's leading rider, aboard.
Hall of Fame trainer Roger Attfield, an eight-time Plate champion, served as the guest drawmaster Thursday at Woodbine.
Dynamic Sky will start from the No. 2 spot Sunday. Casse's other horses include Jagger M (20-1, Shaun Bridgmohan), Kaigun (20-1, Justin Stein) and filly Spring in the Air (10-1, Rosario).
Rosario guided Dynamic Sky to victory in last month's Plate Trial at Woodbine by a nose ahead of His Race to Win. Casse said the son of Sky Messa-Murani can be difficult.
"He doesn't like to run in a straight line, he likes to go and lay on horses . . . . which makes me think maybe he's not putting his best foot forward all the time," Casse said. "He's a tough horse to ride and Joel rides him well, he's a very strong rider.
"In the Plate Trial, I don't think that horse would've won with anybody else but Joel that day. This will be the fourth time Joel has rode him and all I'm going to tell him is 'Good luck.' He's the leading rider in the world right now for a reason. I've done my job and that's to get him there so we'll let Joel handle it from there."
Rosario is listed atop two separate mounts as a precaution. If Dynamic Sky remains healthy leading up to Sunday's race, Rosario will be its rider and veteran Gary Boulanger will be aboard Spring in the Air.
"A long time ago we committed to Joel," Casse said. "If Dynamic Sky were scratched then Joel Rosario, the leading rider in the world, would be sitting watching the race.
"I don't want to take that chance so I put Joel on both. Gary knew of my plans weeks ago and I told him 'Look, you can go and pick another horse and I understand or you can sit and wait and if all goes well you're going to ride Spring in the Air,' and they chose to wait. Unfortunately he's going to have to wait a little bit longer but if both horses are happy and healthy come the Plate, Gary Boulanger will be on Spring in the Air."
Sam-Son Farms' Up With the Birds is the early 2-1 favourite for the 1 1/4-mile race, the first jewel of the Canadian Triple Crown. Filly Nipissing, the '13 Oaks winner, is the 7-2 second choice.
Up With the Birds' handlers selected the No. 7 post while Nipissing will break from the No. 9 spot. Nipissing will attempt to become the 35th filly winner all-time and first since Inglorious in 2011.
Casse won't be the only trainer with multiple starters Sunday.
Malcolm Pierce not only conditions Up With the Birds for Sam-Son Farms but also His Race to Win, a 10-1 pick that will be ridden by Hall of Fame jockey John Velazquez.
Mark Frostad, who won four Plate titles as a trainer with Sam-Son, sends two horses postward: Pyrite Mountain (6-1, Luis Contreras) and County Lineman (30-1, Alex Solis). Nick Gonzalez will also have two in the field: Midnight Aria (15-1, Jesse Campbell) and River Seven (20-1, Todd Kabel).
Up With the Birds has never been worse than third in six career starts and earned a 4 3/4-length win in his last start, the 1 1/16-mile Marine Stakes on May 26. San-Son Farms has won five Queen's Plate races, the last being in 2009 with Eye of the Leopard.
Plate choices have a respectable 38 per cent success rate since 1956 but only Wando (2003 Triple Crown champion) and Eye of the Leopard have won as favourites over the last 18 years.
Nipissing has five wins in seven career starts and the bay filly's $634,430 in earnings is the second-highest in the field. A win Sunday would make Nipissing just sixth horse to capture both the Oaks and Plate.
"It would be the pinnacle of our racing season," said Rachel Halden, Nipissing's trainer. "It's what we all strive for and is why we get up at 4:30 a.m. seven days a week to try and get into this position."
Halden spent 10 seasons as an assistant under Attfield before going on her own five years ago. Halden is still chasing her first Plate win but fiance Steve Bahen, who will ride Nipissing on Sunday, guided T J's Lucky Moon, an 82-1 longshot, to a stunning Plate victory in 2002.
And with Midnight Aria expected as one of the few speed horses in Sunday's field, Bahen isn't sure what to expect.
"We might find ourself maybe a little bit closer if the pace is slower and we'll have to deal with that," he said. "But she relaxes when she gets out there and I'm not going to worry about it.
"If they're going slow I know she's going to have a lot of kick at the end.''