Jaylen Brown kills it in the layup line.

Brown looks the part of a pro. He passes every test in the size and athleticism categories that NBA teams covet at the wing position.

"He's definitely a specimen," an NBA scout told Bleacher Report. "He's big, strong, long, he can run, he can jump. There's not anything he won't be able to do on the floor from an athletic and physical standpoint."

Between the lines, there are some questions about Brown's feel for the game and his jumper. But in a draft that lacks a lot of upside players, Brown has the measurables that can make a scout's imagination run wild for what he could become.

Relevant Stats

Brown has put up solid scoring numbers, but they're not eye-popping. Part of that has to do with the balance of Cal's attack.

"They're a unique team because they have multiple guys who can score and maybe that has caused his numbers to be a little bit less inflated then what's anticipated," the scout said.

Brown's attacking style lends to getting to the line often, and he ranks 28th in college basketball in fouls drawn per 40 minutes, per KenPom.com, tied with LSU's Ben Simmons for tops among draft prospects.

The two numbers on the negative side are his three-point shooting—the worst among small forwards in B/R's latest first-round mock draft—and his turnovers. His turnover rate is the worst among the college small forwards on B/R's draft board.

Strengths

The best part of Brown's game is when he has the ball in his hands and is attacking downhill. Brown is excellent in transition and thrives on going at defenders when they're on their heels. He can finish through contact and draws a lot of fouls.

"He's going to be able to keep up going up and down the floor with most NBA athletes, and that's the first box that you want to check—does he fit on an NBA court, and he does," another NBA scout told B/R. "And then the fact that he flashes some skill on top of that is somewhat reassuring as to where his ceiling may be."

The skill is what often gets overlooked. Brown is pegged as an athlete, but he has more to his game than just overpowering opponents when he's attacking the rim.

The Bears like to isolate Brown near the elbows or in the post, and he's shown some savvy in these situations. He can face up and does a good job of setting up moves with his footwork by using jab steps. He can also make mid-range jumpers when facing up, although he's not consistent from this area of the floor yet.

Brown can also work out of a pick-and-roll as either the ball-handler or the screener. This is still a developing part of his game, but he's dangerous when he is able to turn the corner around a ball screen. 

In the post, Brown does an excellent job of establishing position and giving his teammates an easy target. He's also comfortable playing with his back to the basket.

When Brown is attacking, he's right-hand dominant but able to finish with his left, which helps keep the defense honest.

Defensively, Brown has a lot of upside. Once he figures out how to use his length and quickness to his advantage, he'll be a plus defender at the next level. He's done a good job getting deflections this season, although his steals numbers aren't what you would expect for someone with his abilities.

Similar to his offensive game, Brown is most comfortable on the defensive end in space when he can rely on his athleticism. A good example is his ability to block shots as a weak-side defender or in transition. 

Weaknesses

Brown's jumper will be the biggest concern surrounding him for NBA teams. He not only struggles to make perimeter jumpers, but he's also a mediocre free-throw shooter.

"He's got to improve his shooting," the first scout said. "He's got to be able to survive on the floor as a shooter in some form or fashion."

Brown is getting more comfortable in Cal's half-court offense as the season progresses, and head coach Cuonzo Martin even trusted him with backup point guard duties in a win over Arizona last Saturday, but his overall feel in a half-court setting is something scouts question.

"Obviously he can go downhill off a high pick-and-roll and attack the rim, but he needs to improve making plays for others off a ball screen," the second scout said.

Brown's decision-making when a driving lane does not present itself is one reason his turnover numbers are so high. He often tries to force the issue when it's not there, and he's not a good passer in tight spaces. However, there are instances when he'll drive to kick to a three-point shooter, and this is something he does quite well.

When he does drive and kick, though, it seems that he's made the decision to do so as soon as he starts his drive. Learning how to react to the defense when he gets cut off is something that he needs to improve.

"He's good if you let him do what he wants to do, which is outathlete you and beat you to the rim, but I think what he needs to do is keep developing his mid-range game and jump shot," the second scout said.

NBA Player Comparisons

This left scouts stumped.

"He's a hard one to peg," the first scout said. "I've read he's like Stanley Johnson, and that's just totally inaccurate. Stanley could handle it. His shooting was coming along, and so I don't agree with that one."

Brown's numbers and body type share similarities with Kawhi Leonard when he was at San Diego State. Leonard averaged the same number of assists (1.9) as a freshman, and his scoring numbers as a sophomore (15.5 PPG) are almost identical to Brown's current numbers. Leonard also struggled shooting the three in college, making only 25 percent of his threes in his two years at San Diego State.

Leonard was a much better rebounder in college and played inside more often. Brown is further along as a slasher than Leonard was at that point, and he gets to the line more often than Leonard did as a collegian. Brown has the athletic traits and length that Leonard had as an upside pick in 2011.

Best-Case Scenario

Developing into the type of two-way player that Leonard has become would be the ceiling for Brown, and that's why he's so intriguing—that's a really high ceiling.

Leonard is a 39 percent three-point shooter in his NBA career, and he's knocking down nearly 50 percent of his threes this season. It seems far-fetched to even dream about Brown becoming that reliable as a shooter, but the same could have been written about Leonard when he was drafted.

Brown has a long way to go when understanding how to be a great defender, but like Leonard, he has the length and quickness to get there.

Worst-Case Scenario

The worst-case scenario for Brown is that he is what he is now—an athlete who can slash. It's going to be hard for him to be a valuable piece on a winning team if his jumper doesn't become serviceable and he doesn't improve his feel for the game on both ends. Some athletic wings who were lottery picks and fit that profile include Corey Brewer, Terrence Williams and Al-Farouq Aminu.

"I think you have to draft him conceptually thinking, 'We've got to get him there and we're getting this guy who has the potential to be an all-league type of defender just based on his physical and athletic ability,'" the first scout said. "He's going to need some major skill development." 

That is the risk in taking an upside player who is a project. If those areas of his game don't improve, he's a bench player in the league. 

March Impact

While scouts put varying degrees of importance on a player's performance in the NCAA tournament, with the eyes of the nation on March Madness, playing well or poorly in the most important games of the season can certainly sway one's opinions. Some players like the UConn Huskies' Shabazz Napier have used the tournament as a springboard to rise up draft boards in recent years.

Brown is currently slotted to go eighth in our latest mock draft. He could jump up a few spots with a great NCAA tournament, but it's going to be tough to unseat Ben Simmons, Brandon Ingram or Dragan Bender from the top of the draft. 

It's not a given that Brown will get the opportunity to do so. The Bears (14-6 overall, 4-3 Pac-12) could play themselves onto the wrong side of the bubble in the extremely balanced Pac-12. 

If they do get there, Brown has shown that he elevates his game against Cal's top competition. In three games against opponents that are currently ranked (Virginia, Oregon and Arizona), he's averaged 17.7 points per game.

Prediction

"He's going to be drafted on what he can be, and a lot of it is going to be dependent upon how hard he's wiling to work to improve his skill level," the first scout said. "But as a body of physical presence, he's incredible."

This is why Brown is almost a lock to not fall outside of the top 10, and could end up getting drafted in the top five or soon after. The only players in this class thought to have higher upside are the three at the top and perhaps Providence's Kris Dunn or Cal teammate Ivan Rabb.

Brown will end up going to a team looking for a small forward of the future, and that could include several current lottery candidates: the Phoenix Suns, Los Angeles Lakers, New Orleans Pelicans or Portland Trail Blazers. He's in a good spot because there aren't a lot of small forwards in the draft and it's a position of need for all four of those lottery-bound teams.

C.J. Moore covers college basketball for Bleacher Report. You can follow him on Twitter @CJMooreBR.