Mickey Moniak noticed whenever top Phillies executives surveyed a La Costa Canyon High School game this spring. His coach, Justin Machado, often watched Moniak sneak a peek. The Phillies sent every important decision maker to the school north of San Diego, with Hall of Fame former general manager Pat Gillick at the forefront.

They saw Moniak spray the field with triples and homers. They saw elite speed in center field. They began to dream about the 18-year-old as he reached new feats with every chance to showcase for the Phillies.

"It seemed every time those guys were in town," Machado said, "he just put on a show."

So the Phillies made Moniak the No. 1 pick in Thursday's Major League Baseball draft, the reward for a tedious 99-loss season. This draft was characterized by its lack of a consensus No. 1 pick, and Moniak rose in recent weeks as the Phillies began to weigh talent and money.

The night before his high school graduation, Moniak watched with family and friends at his aunt's house in Carlsbad, Calif. He raised his hands in the air when commissioner Rob Manfred announced his name on MLB Network.

"The No. 1 pick has always been a dream," Moniak said. "Up until the point where the commissioner said my name, it was all a mystery. When it happened, it was unbelievable."

It was not a total mystery, though. The Phillies and Moniak's adviser had negotiated before the pick was made; Moniak was committed to play baseball at UCLA, but he will sign with the Phillies.

"As soon as possible," Moniak said.

It will be years before the Phillies know whether Moniak was the correct pick. Prep players take longer to develop, although in the history of the draft, they are the most successful cohort of players selected first overall. Moniak may not reach the majors until 2020 if everything goes right.

Moniak, 6-foot-2 and 180 pounds, is undersized but has a hitting ability that impressed scouts. Johnny Almaraz, the Phillies' scouting director, said Moniak could play center in the majors right now. He labeled Moniak the best amateur hitter in the country.

"I believe one day he will hit anywhere between 15 and 22 home runs," Almaraz said. "I think you'll have a Gold Glove centerfielder who will hit in the middle of the lineup and be a leader on the team."

Not everyone holds that opinion, but the Phillies believe in their extensive study of Moniak. The Phillies, Almaraz said, had someone at every game Moniak played as a senior. The team evaluated more than 20 reports from their scouts and executives. General manager Matt Klentak was among the many to see Moniak in person.

"It's important to note this is a middle-of-the-field player," Klentak said. "The way baseball is today, that was a major factor for us. This is a kid who is athletic. He can really hit. One of the top bats in the country and he's a centerfielder. That's a pretty good combination."

The Phillies took Moniak because they will sign him with a discounted bonus. The first pick was valued by MLB at $9.02 million. The team's second pick, No. 42, carried a slot bonus of $1.54 million. So the Phillies could split $11 million between their first two picks.

That strategy attracted a first-round talent whose financial demands were high enough to drop to them. They picked Kevin Gowdy, a 6-foot-4 righthanded pitcher from Santa Barbara (Calif.) High School, who also said he would attend UCLA if he does not sign a pro contract.

Gillick, now a senior adviser to Klentak, was said to be an advocate of Moniak as the top pick. Moniak said he talked to both Gillick and Charlie Manuel, also a senior adviser, when they attended his games.

His father, Matt, played baseball at San Diego State. His grandfather, Bill, was signed by the Red Sox in 1958. Bill Moniak spent six seasons in the minors and never played above single A.

Moniak's given name is McKenzie; he said his favorite all-time player is Mickey Mantle. "And not just because of the name," Moniak said. He was born in 1998, less than three years after Mantle died.

Detractors wonder whether Moniak will develop a power swing. A major-league conditioning program will help him. Moniak hit zero home runs as a junior. He smashed seven in his senior season after adding some strength. He hit .476 with a .921 slugging percentage and 12 triples.

"He may grow a little more," a National League executive said. "He's smooth. He's like a Steve Finley centerfielder."

Moniak said his strength is his hitting. Soon, he will be tested at a higher level.

"I take a lot of pride in hitting," Moniak said. "It's something I work on a lot."

More than five hours after the Phillies selected Moniak, team officials filtered out of a conference room that doubled as the draft headquarters at Citizens Bank Park. Klentak and Almaraz held a news conference after midnight. Part-owner John Middleton attended.

Following a 10-minute session, Klentak and Almaraz returned to the war room and stayed there Friday past 1 a.m. to prep for the draft's second day.

And, later this afternoon, Moniak will walk at La Costa Canyon's graduation as the top amateur player in the country. In days, he will be a professional baseball player with the highest expectations.