A 12-time winner from 31 starts, along with nearly $1.5-million in purse earnings, Le Cinquieme Essai, a nine-year-old son of Fastness, attempts to net another win in the seven-furlong test over the E.P. Taylor Turf Course.
"He's 110 per cent coming into this race," said Nielsen. "If he changed his attitude, we wouldn't be running him. But he loves the action, he loves the attention and he wants to do it."
After a narrow runner-up head loss to Vanderlin in the 2005 Play the King, Le Cinquieme Essai began his string of scores in the race one year later, a half-length triumph over Becrux.
In 2007, the chestnut bested Just Rushing by three-quarters of a length over 'soft' terrain.
"For me, his win last year in this race was the most rewarding one. He had come off a suspensory injury, a substantial one and he won the Play the King in his usual gutsy way. A lot of work went into getting him back to the races and he showed a ton of heart."
Nielsen expects the fan favourite to be at the top of his game once again.
"He's been around a long time and I really believe he is one of the most consistent horses in North America," offered Nielsen. "He trains hard and he competes hard."
Overall, Le Cinquieme Essai, Canada's Sovereign Award winner as the country's top three-year-old male in 2002, has 23 top-three finishes to date, including a third to Leroidesanimaux in the 2005 Woodbine Mile.
Last year, he finished eleventh, just six lengths back of Shakespeare in the $1-million turf classic, a race in which he bled.
Le Cinquieme Essai will have his work cut out for him on Saturday. The race has attracted top-notch local talent, including Awesome Action, Just Rushing and Wollemi Pine.
Saeed bin Suroor has a pair of entrants: Emirates to Dubai and Tam Lin, the latter finishing second to 2007 Woodbine Mile runner-up Kip Deville in the Grade 3 Poker Handicap on July 13.
Win or lose, Nielsen is proud of his enduring star.
"I love his courage. He is, in every way, a warrior."
Also on tap Saturday, the $100,000 Silver Deputy Stakes.
FIELD FOR THE PLAY THE KING
Post / Horse / Trainer / Jockey
1 / Emirates to Dubai / Saeed bin Suroor / Jono Jones
2 / Last Gran Standing / Brian Williamson / David Clark
3 / Disfunction / Julia Carey / Chantal Sutherland
4 / Off Duty / Lynn Whiting / Larry Melancon
5 / Just Rushing / Sid Attard / Jim McAleney
6 / Wollemi Pine / Ian Black / Emma-Jayne Wilson
7 / Tam Lin / Saeed bin Suroor / Patrick Husbands
8 / Le Cinquieme Essai / Paul Nielsen / Steve Bahen
9 / Awesome Action / Sue Leslie / Robert Landry
10 / Mulmur / Mark Frostad / Eurico Rosa da Silva
11 / Morada Key / Mark Casse / Corey Fraser