Five years ago, Uncle Mo appeared to be invincible in the Wood Memorial. It looked like a foregone conclusion that the undefeated, reigning 2-year-old champion would dominate at Aqueduct and head for Louisville as the Kentucky Derby favorite.

Not so fast, because Uncle Mo finished third, stunning almost everyone, particularly owner Mike Repole and trainer Todd Pletcher. On Saturday, Repole is rooting for his colt Outwork to do what dad couldn’t: win New York’s $1-million, 1 1/8-mile Derby prep.

Repole, a 47-year-old Nassau County resident who grew up in Middle Village, Queens, has fond memories of learning the game at the funky old Big A. “The Wood for me is so important because it’s in my hometown and at Aqueduct,’’ he wrote in an email to Newsday. “Losing the race with Uncle Mo at 1-9 really was tough. Having Outwork, a son of his, in the race is really special.’’

Outwork, also trained by Pletcher, is the 5-2 second choice to 2-1 Shagaf in a field of eight in the 92nd edition of the Wood, one of Saturday’s three Grade I Derby preps. The Blue Grass Stakes at Keeneland and the Santa Anita Derby, both at 1 1/8 miles, will help firm up the field for the 142nd Run for the Roses on May 7. NBCSN will televise all three live from 5-7 p.m.

The speedy Outwork won his first two starts before fading to second behind stablemate Destin on March 12 in the 1 1/16-mile Tampa Bay Derby. Uncle Mo was 0-for-2 past 1 1/16 miles, and there were doubts about whether he could sire horses that could win at 1 1/8 miles and beyond.

Nyquist, last year’s undefeated 2-year-old champ, proved that he could with his runaway in last Saturday’s 1 1/8-mile Florida Derby. The 7-for-7 superstar of Uncle Mo’s excellent first crop of 3-year-olds will be the Derby favorite. Repole is hopeful Outwork will run well enough to join him in the starting gate.

“Watching Uncle Mo be so successful as a stallion is so gratifying,’’ Repole said. “I never thought he would be a better stallion than he was a racehorse, but he will be.’’

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Like American Pharoah, Uncle Mo stands at Ashford Stud in Versailles, Kentucky, within whinnying distance of the Triple Crown hero. A rare liver ailment kept Uncle Mo out of the Derby, Preakness and Belmont. Pharoah became an immortal last spring, but down the road it will be a major challenge for him to match Mo’s tremendous start at stud.

Repole isn’t concerned about a genetic competition. “I’m so focused on the Wood that I can’t even think about what would be next,’’ he said.

If Outwork runs big, that will change in a hurry.