With Zion Williamson sidelined for the foreseeable future with a knee injury, the door is open for the rest of the 2019 draft class to fill the hole he's temporarily leaving behind in the Rookie of the Year race. Aside from the top five picks, the 2019 class wasn't praised for its depth like the draft class before it, but as we know there's always going to be a handful of players who surprise us.

Now that the season has officially begun, and we've gotten a chance to see most of the rookies make their debut, it's time to put together this season's first rookie rankings list. These rankings will reflect a rookie's performance on a week-to-week basis, not the collective season, so these aren't Rookie of the Year standings. One week a player could be No. 2 on the list, and after that, they could fall out of the Top 10 completely. It all depends on a rookie's weekly performance.

With that straightened out, here is the first Rookie Power Rankings of the 2019-20 season. 

This week's NBA Rookie Power Rankings
P.J. Washington Charlotte Hornets PF
Washington, the Hornets' No. 12 overall pick in the 2019 draft, got basically whatever he wanted from beyond the arc in his debut against the Bulls. He finished the night with 27 points, and his seven made 3-point shots set an NBA record for most 3s for a rookie in their debut. The Bulls clearly didn't respect Washington as a shooter, as they left and ocean's length amount of space for him to get his shots off. It wasn't like he was laboring to put points on the board either --  it only took Washington nine attempts to get the record. He won't keep this scoring effort up throughout the rest of the season, especially now that the cat's out of the bag that he can shoot, but for Charlotte, it has to be excited with the early returns.
Kendrick Nunn Miami Heat SG
After dropping 40 points on the Houston Rockets in the Heat's preseason finale on Oct. 18, Nunn picked up right where he left off, finishing with 24 points and three assists on 55.6 percent from the field in his regular season debut. Nunn, who went undrafted in 2018, got the start in Jimmy Butler and Dion Waiters' absence and made the most of it. He showed off his speed and handles against the Grizzlies in his first NBA game, and got to the rim at will. His final points of the night came off a steal when he deflected a pass that led to a breakaway tomahawk dunk that electrified the American Airlines Arena. The Heat signed Nunn to a multiyear deal on the final day of the 2018-19 season, and so far he's making the most of it. Coach Erik Spoelstra has already hinted that he'll remain in the starting lineup when Butler makes his debut.
R.J. Barrett New York Knicks SF
There won't be many bright spots for the Knicks this season, but one thing they can count on is R.J. Barrett getting buckets on a nightly basis. Barrett, the No. 3 overall pick, finished his Knicks debut with 21 points, five rebounds and two assists. He showed all the confidence in the world against the Spurs, bullying his way to the rim, staying active on defense -- he had two steals -- and playing with the kind of passion and energy that would make even the most cynical Knicks fan get excited. By not playing in Zion's shadow anymore, Barrett looks really comfortable being the focal point on his own team.
Coby White Chicago Bulls PG
White may not be the starting point guard for the Bulls yet, but his NBA debut proved he deserves to be in the conversation as he progresses this season. The UNC standout finished the night with 17 points, seven assists and three rebounds, and only coughed the ball up once in his debut. Depending on how long Williamson is out, and how the Bulls decide to use him going forward, White could be a legitimate candidate for Rookie of the Year. He displayed his killer speed against the Hornets and did a solid job of finding the open man when driving to the basket. It's only one game, but if White keeps progressing he could be the Bulls' starting point guard sooner than later.
Rui Hachimura Washington Wizards SF
During his 14-point, 10-rebound performance against the Mavericks, Hachimura displayed a little bit of everything in his NBA debut. He showed off his strength, getting his first points in the league by working in the post with Kristaps Porzingis and Maxi Kleber draped all over him. He also showed off his mid-range game, and he was really active on the boards. His double-double is the first in Wizards history by a player making his debut since 1994 when Juwan Howard did it. Playing for Japan in the FIBA World Cup over the summer definitely helped Hachimura prepare for his first NBA game, and he showed flashes throughout the night as to what he can become.
Tyler Herro Miami Heat SG
Since his first Summer League game, Tyler Herro has been a fan favorite in Miami, and the hype train continued after his debut against the Grizzlies. Herro dropped 14 points and grabbed eight boards, but the highlight of the night came when he put Grayson Allen on skates. It would've been a perfect sequence if Herro would've pulled up for a jumper, but he opted to pass it instead. The Kentucky product his known for his sharpshooting capabilities, but he was getting it done from everywhere on the floor. Herro's scoring makes him a ROY darkhorse, but even if he doesn't win the hardware, the Heat have a talented young player to develop for years to come.
Nicolo Melli New Orleans Pelicans PF
Before the Pelicans' season opener against the Raptors, there weren't many people who could've told you who Nico Melli was. For those not well-versed in European basketball, Melli is a 6-9, 28-year-old Italian rookie who introduced himself to the league with his 3-point shooting on Tuesday night. Melli had an efficient 5-of-7 night from the field, racking up 14 points on 80 percent from beyond the arc. Melli might not have been on anyone's radar before the season started, but he definitely is now.
Ja Morant Memphis Grizzlies PG
Morant had a tame NBA debut, but it was still impressive nonetheless. He tallied four assists and four rebounds to go with his 14 points on the night and showed hints of superstar ability. Morant's debut didn't grab all the headlines, but he was playing like a seasoned veteran. He wasn't forcing anything, got his teammates involved and was engaged on defense. Morant's college career was filled with high-scoring games, and while he didn't put up 25 or 30 points, his performance showed that those numbers might not be far off if he keeps progressing.
Brandon Clarke Memphis Grizzlies PF
Clarke's first points in the NBA came off a sweet looking 3-point shot. That's not exactly his bread and butter, but it still looked pretty solid. He finished the night with eight points, seven rebounds and one block, and if Clarke can hit that shot at a decent enough clip, he'll be dangerous. He already showed his rebounding capability and he's already a stout defender, if he develops a steady enough 3-point shot, the Grizzlies rebuild could be over quickly.
Darius Garland Cleveland Cavaliers PG
Garland only played five games in college due to a knee injury, and it'll take him a bit to adjust to playing at the pro level. However, his rookie debut was a solid starting point for the Vanderbilt product. Garland finished with eight points, five assists and two rebounds, and on one play, he showed off his sweet ball-handling skills, which dizzied capable defender Al-Farouq Aminu, leading to a step-back 3-pointer. Garland's development, alongside second-year player Collin Sexton will be intriguing to watch throughout the season as the Cavaliers try to build a team around the young tandem.