Fantasy Basketball Week 21 Start/Sit: Is Castle King of the Rookie Class?

We're getting closer to crunch time in both the NBA and fantasy basketball seasons, making our lineup decisions even more critical than usual. Fortunately, the schedule-makers bless us this coming week with an abundance of teams set to play either five (the Nets) or four games, and the typical barrage of late-season injuries and absences are affording us plenty of under-the-radar starting alternatives at each position.

Each week, we'll aim to highlight a pair of Start candidates for your fantasy rosters who may shape up as some tougher calls of the week to make, focusing on players with a start or roster rate of 50% or less in Yahoo leagues. 

Likewise, we'll spotlight one Sit candidate at each position who would normally not be a consideration for a spot on your bench, often focusing on players with fewer game opportunities during the coming week.

TEAMS WITH FIVE GAMES: Brooklyn Nets

TEAMS WITH FOUR GAMES: Atlanta Hawks, Boston Celtics, Charlotte Hornets, Dallas Mavericks, Denver Nuggets, Houston Rockets, Indiana Pacers, Los Angeles Clippers, Los Angeles Lakers, Memphis Grizzlies, Miami Heat, Milwaukee Bucks, Oklahoma City Thunder, Orlando Magic, Philadelphia 76ers, Phoenix Suns, San Antonio Spurs, Toronto Raptors, Utan Jazz, Washington Wizards

TEAMS WITH THREE GAMES: Chicago Bulls, Cleveland Cavaliers, Detroit Pistons, Golden State Warriors, Minnesota Timberwolves, New Orleans Pelicans, New York Knicks, Portland Trail Blazers, Sacramento Kings

Without further ado, let's examine some tougher start/sit decisions for Week 21:

Guards     

Start: Isaiah Collier, Jazz 

34% roster rate

Collier continues to hold down the starting point guard role for the Jazz, and although his backup Keyonte George sometimes outperforms him, the latter is over our 50% start rate threshold. Collier isn't a bad "consolation" suggestion by any means, however, entering Week 21 with averages of 11.8 points, 7.7 assists, 3.7 rebounds and 1.2 steals across 30.2 minutes per contest over his last six games. The Jazz are likely to continue giving veteran players like Collin Sexton, Lauri Markkanen, Jordan Clarkson and John Collins plenty of time off down the stretch, so Collier should be the beneficiary of plenty of extra opportunity as Utah embarks on another four-game week.

Start: Stephon Castle, Spurs

47% roster rate

Castle continued to shine off the bench for the Spurs in Week 20, and he enters the new scoring period on a torrid six-game stretch overall. The rookie has averaged 23.3 points (50.9% shooting), 5.2 rebounds, 4.7 assists and 1.2 steals across 29.2 minutes per contest in the latter span, a stretch where he's been under 20 points just once. Castle was afforded plenty of consistent playing time right from the onset of the season, so he's unsurprisingly looking better than ever down the stretch and has four favorable home matchups on tap in Week 21 (Mavericks twice, Hornets, Pelicans).

ALSO CONSIDER: Cole Anthony, Magic (23% roster rate)

Sit: Fred VanVleet, Rockets   

95% roster rate

VanVleet remains in this spot for another week after missing all of Week 20 and 15 of the last 16 games overall due to his troublesome ankle. The veteran guard is listed as questionable for Monday's game against the Magic, but it would be fair to view that designation with a healthy dose of skepticism. Even with a four-game week on tap for Houston, fantasy managers would be best served treading carefully and looking for other alternatives at guard.

Forwards        

Start: Naji Marshall, Mavericks

45% start rate

Consider yourself fortunate if you can still get your hands on Marshall off your league's wire this week. The one-time undrafted free agent is fully capitalizing on the opportunities created by the Mavericks' tumultuous season from a personnel standpoint, and he heads into Week 21 playing the best basketball of his career. Marshall hit new career-high marks in scoring in each of his last two Week 20 games (29 and then 34 points), and he averaged 25.8 points (52.6% shooting), 10.5 rebounds, 5.0 assists and 1.8 steals across 35.8 minutes in the last four games overall. Marshall appears to have the starting power forward job in hand for the time being with P.J. Washington still suffering from a lingering ankle injury, making the former a very viable starting option with a busy four-game week ahead that includes matchups against three defensively vulnerable teams in the Spurs (twice) and the 76ers.

Start:  Quentin Grimes, 76ers     

45% start rate 

Speaking of players proving adept at filling usage voids created by personnel turnover on their teams, Grimes makes a second consecutive appearance this week after providing 18.8 points, 5.5 assists, 4.5 rebounds and 1.5 steals across 34 minutes per game in four Week 20 contests. That line even factored in a dud in a tough matchup against the Celtics on Thursday where Grimes shot just 2-for-11 from the floor. Tyrese Maxey will open the week questionable against the Hawks on Monday due to the back and finger injuries that have cost him the last three games, but even with a projected return for the star guard at some point in Week 21 – and Paul George (groin) ruled out Monday at minimum – Grimes clearly has a solid complementary role in a worst-case scenario as Philly plays out the string without Joel Embiid (knee).

ALSO CONSIDER: Ziaire Williams, Nets (9% roster rate)

Sit: Paul George, 76ers

59% start rate

As just mentioned in Grimes' entry, George is set to miss at least one more game with the groin injury that's already cost him three of the last four contests, and there's no guarantee he's healthy enough to play Wednesday against the Raptors, either. While he should have additional usage opportunities when and if he does take the court this coming scoring period, George hasn't exactly thrived lately despite Embiid's absence, averaging an ordinary 13.7 points (on 43.2% shooting), 4.5 rebounds, 3.4 assists and 2.3 steals across 34.0 minutes in his last 11 games.

Centers   

Start: Alex Sarr, Wizards 

47% roster rate 

Sarr's production sees the occasional fluctuations that are part of many rookie campaigns, but the second overall pick has shown encouraging signs of improved consistency lately after a three-game absence due to an ankle sprain. Sarr has averaged 14.4 points, 6.6 rebounds, 2.6 assists and 1.0 steals across 26.8 minutes in the last five games, eclipsing 20 points twice and providing one double-double in that span. He's also averaging 1.5 blocks per contest for the season and has even drained multiple threes in 22 of 47 games, making him a truly versatile fantasy contributor that could pay some nice dividends on a four-game week.

Start: Andre Drummond, 76ers 

37% start rate

Drummond has finally overcome a nagging toe injury and started to capitalize on the absence of Embiid, as he'd averaged 10.8 points, 11.0 rebounds, 2.2 assists and 1.0 steals in the six games leading into a Sunday victory over the Jazz where he sat out the second half after coming into the day dealing with an illness. Drummond's status for the second leg of a back-to-back set Monday against the Hawks bears monitoring, and if the big man is ultimately ruled out and therefore only has three other chances to take the floor in Week 21, the Jazz's Kyle Filipowski, listed as an alternative option below, is certainly a very appealing pivot. However, assuming the possibility of a four-game week, Drummond has plenty of upside as the Sixers' starting center and has a double-double within his range of outcomes any time he sees a normal allotment of minutes.

ALSO CONSIDER: Kyle Filipowski, Jazz (38% roster rate)   

Sit: Domantas Sabonis, Kings

50% start rate

The Kings have only three games on their Week 21 docket and Sabonis appears all but certain to miss at least Monday's contest against the Knicks with the Grade 1 hamstring strain that knocked him out for all of Week 20. Sacramento does have plenty of postseason-related incentive to get the big man out there as soon as possible, but the coaching staff will also have to balance those objectives with Sabonis' longer-term availability if they do get into the Play-In Tournament. With a capable veteran in Jonas Valanciunas doing a very good job in Sabonis' stead thus far, there's a chance we get a very abbreviated week from the latter in a best-case scenario.