Check out some highlights of Knicks forward Kristaps Porzingis working out in his native country of Latvia over the offseason. (1:03)

LIEPAJA, LATVIA -- The mornings were toughest for Kristaps Porzingis.

With his 7 a.m. alarm blaring and Spanish class nearing, his eyes began to open. But the urge to fall back asleep was overwhelming.

There are certain requirements of a professional basketball player's job. Near the top of the list: getting out of bed. It sounds simple, but it was a struggle.

"To close your eyes was the best feeling. It was unbelievable," Porzingis said. "It's just like a feeling in the stomach; you can't really describe it.

"It's something you can't resist."

So, more often than not, Porzingis would close his eyes. He'd eventually wake up -- usually around 1 p.m., after about 14 hours of sleep -- and head to practice with Sevilla's junior team.

Photos: Camping with Kristaps The Knicks' rising star Kristaps Porzingis returns to Latvia for his youth basketball camp ... and of course a little fun while he's back home. Gallery

But even after more than a half-day's worth of sleep, the fatigue lingered.

"I would run three times up and down the court in practice, and I would be dead tired. Not sweating at all. But dead tired, breathing like crazy," he said. "And it was just the worst feeling ever. I was really struggling.

"I couldn't run, I couldn't do anything. And I didn't know what was wrong."

Sevilla coaches and management were equally concerned. They had a 6-foot-9 prospect who weighed around 160 pounds and could barely complete a practice. In the first weeks of his professional career in Spain, Porzingis seemed destined to fulfill the worst stereotypes of the European big man: a player too weak to fulfill the promise his size engendered.

No one knew then that Porzingis was suffering from anemia, a blood disorder that leads to extreme fatigue and weakness. It went undiagnosed for about six months, and it was killing the young prospect.

"It's all I would think about," Porzingis said. "'What's wrong with me? Why am I like this?' It was an everyday fight. And I used to get emotional, because I would be giving everything I had [in practice] and I just couldn't do it. I thought, 'Why can't I do the things that everyone else is doing?' I was just thinking I'm soft, you know?"

Yes, the label that dogged Porzingis during his first few weeks in the NBA was a very real concern for him at 15. Eventually, Sevilla doctors diagnosed Porzingis' condition. He began treatment, which included taking iron pills daily, and started to feel like himself again.

"I started to open up," he said.

Kristaps Porzingis taking flight at the KP6 Basketball Camp in his hometown of Liepaja, Latvia. Pete Kiehart for ESPN

By now, the NBA world knows Porzingis' story.

After being booed on draft night last year, Porzingis shattered stereotypes and statistical benchmarks in his rookie season with the New York Knicks. He became the first rookie in NBA history to score 1,000-plus points, grab 500-plus rebounds, make 75-plus 3-pointers and record 100-plus blocks, according to Basketball Reference research. He also led all rookies on a per-game basis in blocks (1.83), and he was second in rebounds (7.3) and third in points (14.3).

Porzingis' presence and promise changes the calculus for a Knicks team that won a conference-worst 17 games in 2014-15. Team president Phil Jackson has a player who gives him a chance to build a sustainable future in New York.

But how did Porzingis get here? How did the skinny, sleepy Spanish League prospect develop into the kind of talent that has the power to alter the course of a franchise?

On a recent afternoon in a gym in his hometown of Liepaja, Latvia, a port city tucked into the Baltic region of Northern Europe, Porzingis provides an answer to that question. It's the third day of his four-day "KP6" camp -- a training ground for some of Latvia's top young players -- and he wakes up feeling a bit groggy.

The fatigue isn't related to anemia; that has been corralled for some time. But Porzingis has been busy playing host over the past two days. He has taken some of the traveling media to different spots around his hometown: the beach on the coastline of the Baltic Sea, where he and his family spent many summer days; the courts where he grew up playing; and the local hangouts.

"It's all I would think about. 'What's wrong with me? Why am I like this?' It was an everyday fight. And I used to get emotional, because I would be giving everything I had [in practice] and I just couldn't do it."

He has also spent time entertaining some old teammates from Sevilla and the Knicks who came for the camp, including Kyle O'Quinn, Sasha Vujacic and Kevin Seraphin.

Porzingis' brother and manager, Martins, sees that his brother is tired and suggests he take the morning off. Kristaps dismisses the idea immediately.

"No way," he says. "I'm going to work."

Later that morning, Porzingis is back in the gym.

After lifting weights, Porzingis is working with Knicks assistant Josh Longstaff on his shot and on his first step from the perimeter -- two skills that should be useful in new Knicks coach Jeff Hornacek's offense. It's the type of diligent work -- and attention to detail -- that has helped Porzingis establish himself as one of the top young big men in the NBA.

The workouts in mid-June, along with the previous workouts plotted out by Knicks trainer Mubarak Malik and under the watchful eye of his other brother, Janis, have focused on strengthening his lower half. But those who assume that Porzingis is putting on another 15 pounds of muscle mass might be disappointed.

"We understand that he doesn't have to be bigger," Janis says. "Whoever thinks differently, let them think that. But he's a different player. He's going to be just stronger -- all of his body will be a little stronger -- but he won't have the [significant increase in] weight. He will still be around 240. And he's going to be like that for a long time I think. Maybe 245, but that's about it."

That might upset those who think Kristaps should develop into a hulking Dwight Howard-type. But Janis believes keeping his youngest brother at a manageable weight will help him impact both sides of the floor by changing shots at the rim and rebounding.

"The heavier he will be, the more difficult it's going to be for him to do that. We just need explosiveness and strength," says Janis, who played professionally in Europe for 10 years. "We don't really need muscle mass. He's a guard in a big man's body. That's what he really is. We kind of look at what he has and try to work on that -- not try to make him into something else."

Kristaps Porzingis brought Knicks teammate Kyle O'Quinn, left, along for the ride in Latvia. Ian Begley

Porzingis' time in Liepaja hasn't been focused entirely on basketball.

In addition to hosting the youth camp, Porzingis has built a new outdoor court near the beach.

The unveiling of the court confirms Porzingis' growing celebrity. Veteran journalists have already hailed him, at 20, as Latvia's most famous citizen. Some die-hard locals wake early in the morning -- or stay up late at night -- to watch Porzingis' Knicks games, which usually tip off around 3:30 a.m. local time.

There are at least 200 locals on hand for the court unveiling, and Porzingis is joined by politicians from Latvia, including Liepaja mayor Uldis Sesks, who dons an oversized Porzingis jersey for the occasion. The man of the hour gives a speech to welcome everyone and is then surrounded by dozens of young children looking for an autograph or a selfie -- some piece of Porzingis. He's happy to oblige.

"He loves kids, so this is great for him," Martins says.

It's the adults who can be a bit concerning. Martins has seen middle-aged men run across traffic in New York in an attempt to get a picture with Kristaps.

"To risk your life for a picture? " Martins says with a chuckle. "It's crazy."

The attention in Liepaja is a bit more relenting. A group of young boys wait for Kristaps to finish a photo and video shoot on the beach before asking for a picture. Two teenage girls wait outside of the gym for Kristaps to finish practicing before politely approaching for a picture.

"This is the stuff that he's happy to do," Martins says.

Kristaps, of course, sees a part of himself in the young autograph seekers. Yes, he's a young NBA star, and he represents the hope that a pessimistic Knicks fan base can cling to, but first and foremost, he is a son of Latvia.

"This is home," he says.

Uldis Sesks, mayor of Liepaja, is just one of the many fans of hometown hero Kristaps Porzingis. Pete Kiehart for ESPN

Early on, Porzingis wasn't obsessed with basketball.

He played many sports growing up in Liepaja, including soccer and swimming. Like most other kids his age, Porzingis also liked to play computer games with friends -- Counter Strike and The Sims were among his favorites -- and ride his bike around town.

"Normal stuff," said Rihards Ozolnieks, a lifelong friend of Porzingis.

Porzingis and Ozolnieks didn't have to face the harsh realities that Janis Porzingis, 35, lived through as a young child in Liepaja. Until 1990, Liepaja was under Soviet rule, and early on in the post-Soviet years, the country's economy lagged. Goods and food were scarce.

Things rebounded by the early 2000s, during Kristaps' childhood, but old, drab Soviet architecture remains in pockets of Liepaja.

Porzingis is aware of the difficulties his family faced, but he largely avoided the hardships and was able to hone his natural talent. At the age of 6, he began playing basketball with Ozolnieks for a local youth team and quickly stood out because of his size and shooting ability.

Porzingis' sleight frame, however, was a mitigating factor against elite competition. The Latvian Under-16 team coach left Porzingis off the roster, deeming him too thin to make an impact.

"His body was still growing and he had no strength," said Pere Gallego, a Spanish agent who negotiated Porzingis' first pro contract with Sevilla in 2010. "He was not able to show his talent on the court beyond some punctual sparks."

Those sparks were promising, but Porzingis struggled with the effects of anemia in his first season with the junior club in Sevilla. He suffered through unending fatigue for six months, but things returned to normalcy once doctors diagnosed the issue.

"I was a different person," he said. "I was myself again and everything became much easier."

Just a big kid himself, Kristaps Porzingis always makes time to talk shop with his young campers. Pete Kiehart for ESPN

Porzingis gradually put on weight and started producing. Soon after, the NBA took notice.

In 2014, the Orlando Magic showed strong interest in selecting Porzingis with the 12th pick of the draft. But Porzingis withdrew shortly before the deadline, opting to return to Sevilla. He continued to progress in Spain and his draft stock rose, but questions about his weight lingered.

With the help of Sevilla trainer Larry Sanders, Porzingis gained about 15 pounds during his final season with Sevilla. However, some NBA teams still had concerns about his weight and durability.

"I told him he's going to get the weight questions for the rest of his career," Sanders said. "You're never going to be big enough to make anybody happy."

He was big enough to make at least one person happy: Knicks advisor Clarence Gaines. Gaines, a front office member who enjoyed a close relationship with Phil Jackson, watched Porzingis in Spain several times during the 2014-15 season and came away impressed. He implored Jackson to select Porzingis months before the draft. Jackson listened and Porzingis flourished.

"They're asking, 'Hey, tell me about Kristaps Porzingis. We want to know, what is he like?' He was an icebreaker. It was like, if you are talking about Porzingis, it means we are friends."" Liepaja City Councilman Gunars Ansins

Porzingis is now even improving international relations between Latvia and the United States.

Yes, international relations.

Gunars Ansins, a Liepaja City Councilman, recently hosted politicians from several countries, including the United States, to discuss NATO and the safety of the region. During the meeting, Ansins fielded many questions about the Knicks' star rookie.

"They're asking, 'Hey, tell me about Kristaps Porzingis. We want to know, what is he like?' He was an icebreaker," Ansins said. "It was like, if you are talking about Porzingis, it means we are friends."

It was just a throwaway line among politicians, but Porzingis as a talking point at a NATO meeting is indicative of his potential global reach.

The Knicks are well aware of this; Porzingis' unique skills -- and potential market command -- have influenced the way they'll approach their future.

Jackson has discussed internally the possibility of building the roster incrementally over the next few summers, with the goal of surrounding Porzingis with a formidable roster when he's ready to lead a team, according to sources.

It's only natural for the team president to think in those terms, of course. But in Carmelo Anthony and Porzingis, Jackson has to consider the futures of two players on the opposite end of an NBA lifespan. Jackson's trade for Derrick Rose last week suggests that he's not ready to blow things up and build solely around Porzingis at this time.

"He's not ready to shoulder any burden on himself," Jackson said of Porzingis. "He's not a neophyte, but he's still very young in this game."

Still, because both players are in New York, speculation about Anthony's future with the club as it relates to the Porzingis timeline will never cease.

Kristaps Porzingis and Carmelo Anthony have quickly formed one of the better 1-2 punches in the NBA. AP Photo/Jason DeCrow

If Anthony ultimately decides to waive his no-trade clause this summer to leave New York, it won't be due to any ill feelings toward Porzingis.

Anthony initially had reservations about the Knicks drafting Porzingis, but the two formed a strong bond last year.

"It wasn't forced," Porzingis said of his relationship with Anthony. "Sometimes you try to force it, because you want to be friends with the leader, you want to be cool with him. But I gave him his space. I'm a rookie; I'm just testing everything. I don't want to bother anybody. It was really natural how our friendship evolved.

"He's a guy that I'm looking up to, I'm learning from, and that's why I think he respects me. I respect him a lot, and that's why this relationship is working."

Anthony and Porzingis give the Knicks one of the top forward tandems in the Eastern Conference, but the club needs help. To that end, the Knicks will have at least $30 million to spend in free agency this summer and hope to fill various holes in the roster.

No matter whom the Knicks obtain this offseason, they seem to be several years away from competing for a title. Porzingis knows this. He lived through last season's 32-win campaign. But he also knows how desperate the city is to build a winner.

"That's the only goal. That's why I'm in the league," Porzingis said of winning a ring in New York. "That's what the fans want; that's what we want. So there's no other thing we're trying to do. But we've got to go step by step. And we've got to keep building."

Porzingis has been doing his part, committing to four-hour individual workouts six days a week while in Latvia. Admittedly, there are times when he'd rather be doing something else. Running through the same drills while an older brother instructs and critiques you can get stale.

In those moments, Porzingis finds himself thinking about his early days in Spain, when he was fighting through a mystery ailment. He thinks about struggling through those first workouts, being enveloped by exhaustion and confusion -- and pushing through all of it. Suddenly, the prospect of running hard for another hour or so isn't so daunting.

"I think that's what makes him who he is now," his brother Janis said. "Because he could've been a big man and he could've be soft and so on. He's not.

"Now he feels like he can push through pretty much anything."