For most NBA rookies, the biggest adjustment they have to make isn't the higher level of competition or the much longer season, it's going from star to role player.
The vast majority have been the best player on their team since they were children. The offense ran through them and the ball found its way into their hands at the end of games. Defensively, they could afford to rest and rely on their superior athletic ability.
But only three rookies -- John Wall, DeMarcus Cousins and Blake Griffin -- were primary offensive options last season. The rest became role players, trying to impact the game without the ball in their hands, which requires a much different skill-set.
A good on-ball player drives to the rim and creates shots for others; a good off-ball player knocks down open shots and has the versatility to defend multiple positions.
Fields, a second-round pick of the New York Knicks, was so lightly regarded out of Stanford that he wasn't one of ESPN's Chad Ford's Top 100 prospects. Neal was never even drafted, spending three years in Europe before being picked up by the Spurs as a free agent last summer.
As rookies, both excelled spotting up off of their All-Star teammates; Fields shot 39 percent from beyond the arc while Neal shot 42 percent. And at 6'7 210 and 6'4 210 respectively, both could defend multiple perimeter positions, allowing them to play alongside a variety of different players.
Conversely, Evan Turner struggled mightily for the Philadelphia 76ers despite being the consensus No. 2 pick. At Ohio State, Turner was a 6'7 205 point forward surrounded by knock-down three-point shooters, winning the Naismith Player of the Year Award and displaying great play-making ability for his size.
But the 76ers already had Jrue Holiday, Andre Iguodala and Lou Williams dominating the ball on the perimeter. Turner, neither a great outside shooter nor a superior athlete, was ill-suited to being a role player, losing minutes to Jodie Meeks (a knock-down shooter) and Andres Nocioni (a feisty and versatile defender).
And while Fields and Neal aren't nearly as talented as Turner, Philadelphia will have to re-arrange their roster to maximize Turner's skills.
Jimmer Fredette, who succeeded Turner as the Naismith winner, will have similar struggles on whatever team drafts him. Jimmer shot the ball nearly 21 times a game at BYU, more than double the number of the Cougars' second leading scorer; there would be a full-fledged locker room revolt before that happened in the NBA.
He's not a true point guard, averaging nearly as many turnovers (3.5) as he did assists (4.2), and at only 6'2 195, he doesn't have the size to be an NBA shooting guard. His primary value for NBA teams will be his ability to space the floor with his jump-shooting ability, but there are several lesser-regarded prospects who can do that without being defensive liabilities.
One such player is David Lighty, a former teammate of Turner at Ohio State. An athletic 6'5 220 guard, Lighty combines quick feet with a lengthy wingspan and showed the ability to play suffocating defense against NBA prospects like E'Twaun Moore in Big Ten play. Offensively, he is already comfortable spotting up off the ball, shooting 43 percent from long-range while spacing the floor for Jared Sullinger.
Kawhi Leonard, another mid-major star, has been rocketing up draft boards after a stellar sophomore year for San Diego State. An athletic 6'7 225 small forward, he averaged 15.5 points and 10.6 rebounds for the Aztecs.
But as Turner found out, it's hard to be an effective NBA role player without a three-point shot, which is the biggest hole in Leonard's game. A 25 percent career three-point shooter at SDSU, Leonard's defender will play off him in the NBA, forcing the offense to play 4-on-5 or live with Leonard firing away from the three-point line.
In contrast, Florida State's Chris Singleton has been under the radar after breaking his foot and missing a big chunk of ACC play this year. But at 6'9 225, he's nearly as athletic as Leonard despite being big enough to also defend NBA power forwards. More importantly, he shot 37 percent from beyond the arc, allowing him to space the floor effectively.
In looking at how college players will transition to the NBA, it's important to look at what role they will play for their pro teams. Fredette and Leonard would do more with 15-20 shots a game than Lighty and Singleton, but the latter duo can help in more ways off the ball.
And as Turner and Fields showed last year, just because a player is a better collegian doesn't necessarily mean they will be a better pro.