Days of rain, which is expected to continue Saturday, have turned the Pimlico track into a shallow lake. (Patrick Semansky/Associated Press)

By midday Friday, the eve of the running of the 143rd Preakness Stakes, the rain and mud threatened to overtake Pimlico Race Course. Water collected in puddles and ran in streamlets in the nooks and crannies of the ancient, creaking building. Bulldozers, pickup trucks and bucket brigades crisscrossed the grounds, moving the wet stuff from one place to another. The track itself, by then a brown, elliptical lake, should have been downgraded from “sloppy” to “biblical.”

A scenario much like this, plus a field of seven upset-minded rivals and a crowd that could still reach 100,000 despite a dreadful forecast, is expected to confront the champion chestnut colt known as Justify at 6:48 p.m. Saturday, when he takes aim at the second leg of the Triple Crown.

The conditions, including a rain chance estimated at 90 percent, might be bad enough to make any living creature want to stay indoors, such as Justify’s temporary home in Stall 28 of Pimlico’s stakes barn, and question why anyone else would do otherwise. Justify, though, already answered that question two weeks ago.

On May 5 at Churchill Downs, the strapping son of Scat Daddy outran a 20-horse field to win what was dubbed the wettest Kentucky Derby in history, kicking through the slop to hold off rival Good Magic by 2½ lengths and keep his career record perfect at 4 for 4 by a combined margin of 21½ lengths.

He will enter the No. 7 starting gate Saturday — same as he did in Kentucky — as an overwhelming favorite, his morning-line odds set at 1-2, which, if they hold, would give him the shortest odds of any favorite since Big Brown, who went off as a 1-5 favorite in 2008 and cruised to a 5¼ -length victory.

“He’s showed us what a truly gifted horse he is,” said Bob Baffert, Justify’s trainer, who will be seeking his seventh win in the Preakness and 14th in a Triple Crown race. Four other times, Baffert has brought a horse to Pimlico following a win in the Derby, and all four times he won. “What he’s done in a short period of time, it takes a really special horse to do.”

It seems like ages ago that people were questioning whether Justify owned enough race experience to win the Kentucky Derby. Before him, no horse in 136 years had won the Derby after not racing as a 2-year-old. But now, the opposite question is being asked in some circles: whether Justify has been pushed too hard. The Preakness will be his fifth career start, all of them in a span of about three months.

“There’s still an opportunity to close the gap on the horse,” said Chad Brown, the trainer for Good Magic, who at 3-1 was the second choice. Brown’s horse, Cloud Computing, won last year’s Preakness. “If our horse moves forward and [Justify] regresses in any way — and that’s a lot to ask for a horse that has moved forward in every one of his starts — but you have to be optimistic [that] you might be able to make up some ground on him. He’s going to have five races in just over 12 weeks, which is hard to do.”

Justify, shown with exercise rider Humberto Gomez aboard, is an overwhelming favorite to win the Preakness and enter the Belmont Stakes with a shot at the Triple Crown. (Patrick Semansky/Associated Press)

Besides Good Magic, only two other horses beaten by Justify at Churchill Downs are bothering to give it another try at Pimlico, including Bravazo, who is saddled by Hall of Fame trainer D. Wayne Lukas and who ran sixth in the Derby. Four other, fresher rivals will line up Saturday having skipped the Derby, most notable among them Quip, the Tampa Bay Derby winner and Arkansas Derby runner-up, who was installed as the third choice at 12-1.

But they all can expect to be chasing Justify at some point during the 1 3/16 -mile race, if not the entirety of it.

“I think it’s a very good field [and] a very good 3-year-old crop, but Justify, to me, is the dominant horse,” Lukas told reporters. “And the fact that he’s so lightly raced and now that he’s got the Derby under his belt, he should get better. Bob’s horses generally always stay in top form. I think it would be silly for us to think he’s going to be less than tough in this race. I expect him to run a huge race in the Preakness.”

The last remaining question about Justify — the status of a bruise on his left hind heel believed to have been suffered during the Derby — appears to have been answered this week, both in repeated assurances from Baffert and more vividly in Justify’s spirited gallops, including one during a lull in the rain Friday at 5:30 a.m.

With just eight horses, this Preakness field is expected to match the ones in 2000 and 2015 as the smallest this century, and should any of them scratch — as no fewer than 44 entries did across 14 races Friday, owing in large part to the abysmal conditions — it could be the smallest since 1986, when only seven started. The sheer numbers mean the race is likely to unfold much differently than did the Derby.

“I don’t think anybody’s going to be in a real big hurry,” Baffert said Friday. “With 20 horses you have to be in a hurry just to stay out of danger. . . . The Derby is a completely different mind-set.”

With another win Saturday, Justify would head to the Belmont Stakes in three weeks with a chance to complete his historic mission — “It’s his Triple Crown to lose,” Lukas conceded — much as another Baffert horse did in 2015. That year, American Pharoah swept the three races to become the 12th Triple Crown winner in history and the first in 37 years. Baffert sees more than a little of that great champion in this one.

“He has this presence about him,” Baffert said of Justify. “What he’s done since February — you have to be a superstar to do that. He’s like Pharoah. They’re superstars.”