The 12th player summoned this season from the minors to make his major-league debut with the Phillies arrived Thursday at Citizens Bank Park and found his name above a corner locker, one reserved for established veterans. He had No. 70 written on his shower sandals, but Rhys Hoskins was here now, and the Phillies do not anticipate him leaving. He needed a number to reflect that. A number like 17.

"Hopefully it's something that I'll remember for a long time," Hoskins said, hours before he stepped onto the grass in South Philadelphia.

Hoskins had months to prepare for this moment. He clobbered 67 homers at Reading and Lehigh Valley, and he could have been here long before Thursday. He has hit ever since the Phillies drafted him in the fifth round from Sacramento State. He hit his way onto prospect lists and T-shirts with an alliterative nickname.

He became a part of the Phillies' plan, albeit at an unexpected position — left field. Hoskins walked in his third plate appearance Thursday night after striking out and grounding into a double play. He had two routine putouts in left field.

"We think his bat is ready to come to the big leagues and stay in the big leagues," Phillies general manager Matt Klentak said.

The club views Hoskins' long-term future as a first baseman. He will spend most of August in left field, with some occasional starts at first base, until Aaron Altherr returns sometime in September from a hamstring injury. Then, the Phillies could carve into Tommy Joseph's playing time by inserting Hoskins as the everyday first baseman.

So Hoskins, 24, batted seventh and played left field in his debut. He will not be an expert fielder, but it is a makeshift solution. The Phillies did not see a reason to crush Joseph's value, especially when there was a hole in the outfield that Hoskins could fill for a little bit.

"The whole goal is to find good hitters," Phillies manager Pete Mackanin said. "I told Tommy he's a good hitter and so is Rhys Hoskins and we want to get as many good hitters as we can. 'I'm not throwing you by the wayside, you're going to play too.' "

A September call-up for Hoskins would not have provided as clear of a picture, Mackanin said. But 150 at-bats is a better sample size.

"I'm going to get him as many bats as I can," Mackanin said. "I'm not going to promise to play him every day, but I'm going to play him as much as I can, which should be a lot."

While with the IronPigs this season, Hoskins hit 29 homers, the most for a Phillies triple-A player since 1971. Almost as impressive: He struck out only 11 more times than he walked with the IronPigs. Power hitters with plate discipline are a commodity, and Hoskins has fit that profile throughout his minor-league career.

In college, Joey Davis saw a player with more moderate power, maybe 15 or 20 homers in the majors. Davis is a Phillies area scout, in his 14th year with the team, and he followed Hoskins in high school and college. He was in the draft room when the Phillies selected Hoskins with the 142nd overall pick.

"The power, luckily he developed it," Davis said. "You never know as a scout if it's going to come or not. I knew he had the body. I knew he had the work ethic. And I knew he was a good hitter."

Davis, on Thursday, considered the total effort that led to Hoskins' ascension. The general manager and scouting director who were in charge when Hoskins was picked have since been fired. Andy Tracy, the team's minor-league hitting coordinator, tweaked Hoskins' stance. Hoskins added a leg kick that allows him to generate more loft — and power from his lower half. And Hoskins had to welcome adjustments and suggestions, all while keeping his body conditioned.

"With scouting, it's a team effort," Davis said. "We have to give them good players and they have to do a good job of coaching. That's what happens. You have a kid like this who is willing to learn and put in the work. He has the body and the size [at 6-foot-4, 225 pounds]. So it was worth a shot in the fifth round."

Hoskins learned the news of his promotion Wednesday night when triple-A manager Dusty Wathan called him into his office. "Sit down," Wathan told him, "I want to have a conversation with a big leaguer." Hoskins called his dad, at home in California.

"That is something I will never forget," Hoskins said. "It was emotional. It's something I've thought about doing for 15, 20 years."

So No. 17 grabbed his glove, played catch with his new teammates, and began what the Phillies hope will be a career that one day involves winning at Citizens Bank Park. Hoskins won't change a thing, not yet.

"It's worked so far," Hoskins said. "I'll make adjustments; it's a game of adjustments. But until that has to be done, I'll stick with what I've done."