Few assets in the NBA are as valued as lottery picks as general managers go to great lengths to put pick protection on traded first rounders.

But there is evidence that they are not quite as valuable as perceived internally.

Of the 70 lottery picks between the 2004 NBA Draft and 2008 NBA Draft, 24 are already out of the NBA, representing 34 percent. This five-year sample covers Dwight Howard's draft class to the one headlined by Derrick Rose.

The Los Angeles Lakers are already beginning to do due diligence on Dante Exum.

''I got a call from the Lakers asking about him and they may end up with a good pick," Luc Longley said.

''I've had a few calls from other NBA teams mostly asking about him, they see the skill package but these days they're all concerned about character.

''That will help push Dante further up the draft, because he's the type of person they'd want to have in an organization."

Exum declared for the NBA Draft this week and will be represented by Rob Pelinka.

Longley has offered Exum advice on adapting to the NBA spotlight and handling the intense scrutiny afforded to high draft picks.

''I was around him all summer with the Boomers and he showed more poise than I expected, his decision-making is very good,'' he said.

Julius Randle entered the season as a candidate to go first overall in the 2014 NBA Draft, but he has seemingly dropped as scouts have taken a closer look.

Some scouts are beginning to prefer Noah Vonleh of Indiana as a better power forward prospect than Randle.

Vonleh doesn't have the same type of "star" potential, but he is bigger and longer than Randle. Vonleh also has a higher rebounding rate on the defensive glass.

Joel Embiid has emerged as one of the top freshmen in college basketball.

Embiid has only been playing basketball for a few years, but has remarkable instincts for the game.

Embiid has also been researching the college tenures of big men such as Hakeem Olajuwon, Tim Duncan and Shaquille O'Neal. The common denominator with those three legendary bigs is that they each spent at least two seasons in college.

"I was curious because I want to be great, I want to be the best at my position one day," said Embiid. "I'm trying to learn everything and what other people did. All of the great big men went to college at least two or three years. I think it's a big factor. I don't know if it will always work, but I think it's the best choice."

"He's the best," Bill Self said. "He wants to know everything. He's so naïve, in a very innocent way. Like certain guys can be naïve to the ways of the world, but he's naïve about everything -- what to eat, everything."

Dante Exum and his family have met with several agents in Australia and it is believed he will skip college to enter the 2014 NBA Draft.

Exum is widely expected to be one of the top half dozen picks with a chance to go higher based on the workouts.

"I would be shocked if he doesn't enter the draft," one agent who recently met with Exum's family told Yahoo Sports. "He knows he's a lottery pick, and knows several teams have him very high on their boards. His family knows that this is an opportunity that may not come again."

Another agent who traveled to Australia told Yahoo: "This is a bright, thoughtful kid – a great family – and they're taking their time to think all this through. But in the end, I didn't sense anything that would hold him back from [the draft]. … I can't imagine him not coming out."

Exum's family has been careful to preserve his college eligibility and leave open the option for him to pursue college basketball. Exum has visited Indiana and may visit others before the season is over.

Exum's father, Cecil Exum, played at North Carolina.

Jabari Parker would almost certainly be a top-3 pick if he declares for the 2014 NBA Draft, but it isn't a lock that he leaves Duke after just one season.

Parker, as a member of the Church of Jesus Christ of Latter-day Saints, may also go on a mission.

"I'm told a Mormon mission still isn't out of the question for him," wrote Chad Ford. "I asked several GMs about what would happen to his draft stock if he declared for the draft and then said he was going on a two year mission. I was surprised how many of them said they'd still consider him with the No. 1 pick."

Julius Randle started the season strongly with Kentucky, but expectations have been tempered by NBA scouts or general managers.

"NBA teams still like Randle, a lot, but I haven't really heard a team (GM or scout) say they'd take him No. 1 in over a month," wrote Chad Ford.

Andrew Wiggins and Jabari Parker are the likely candidates for the top overall pick, while Joel Embiid and Dante Exum are darkhorses.