Deandre Ayton and Marvin Bagley III have been conspicuous in their absence this season. The top two picks of the 2018 draft haven’t played since opening night. Ayton is serving a 25-game suspension for testing positive for a banned substance, while Bagley is sidelined with a broken thumb. But even when the two big men were on the floor as rookies, they weren’t as valuable as Luka Doncic or Trae Young, two players who also went in the top five. Now, with Doncic in the MVP race and Young putting up astronomical numbers, there will be even more pressure on Ayton and Bagley to deliver on their promise when they return.

But neither the Suns, who took Ayton at no. 1, nor the Kings, who took Bagley at no. 2, can live in the past. With the middle of the West weaker than it has been in years, the two long-suffering franchises are in the thick of the playoff chase. Adding an elite young talent, in theory, should make both teams better. But integrating Ayton, who is eligible to return December 17, and Bagley, who could be back as soon as next week, won’t be as simple as it seems. The challenges facing Phoenix and Sacramento show just how difficult it can be to develop young big men—while trying to win—in the modern NBA.

The Suns were the league’s biggest surprise in the first month, with a 7-4 record and feel-good victories over the Clippers and 76ers. They were doing just fine without Ayton. Their problems began when Aron Baynes, a 32-year-old journeyman whom they acquired in a salary dump from the Celtics this offseason, went down. Baynes has quietly turned himself into one of the most indispensable players in the league. Phoenix is 2-6 since he injured his hip and then his calf in late November, and is now hanging on to the no. 8 seed with a 9-11 record.

Baynes made the Suns significantly better on both ends of the floor. He has always been a good defender. The Australian is a smart and tenacious player who is hard to move (unless he’s throwing himself to the ground while drawing a charge) and is rarely in the wrong place. He doesn’t possess the freakish athleticism Ayton does, but he’s a savvier player. Baynes, who is in the 87th percentile of defenders leaguewide this season when defending the screener on the pick-and-roll, knows when to contest shots and when to drop back farther and protect the rim:

The big revelation from Baynes this season has been his offense: The veteran center is averaging career highs in points (14.7) and assists (2.9), and is a shade off his career high in field goal percentage (56.3). After experimenting with a 3-point shot in Boston, he’s transformed into a legitimate stretch 5, shooting 43.9 percent from 3 on 4.4 attempts per game. Even if he can’t maintain those percentages, the sheer number of 3s that he takes means that opposing centers have to respect his shot, which opens the lane for everyone else.

Baynes is a hyperefficient release valve for the Suns. He’s averaging the fewest touches (38.8 per game) in their starting five and the highest true shooting percentage (67.7). He finishes plays, sets devastating screens, and makes good decisions with the ball, with an assist-to-turnover ratio of 2.6-to-1.

The eight-year NBA veteran is a master of the little things. His value isn’t always obvious when he’s in action, but it becomes clear when he’s off the floor. The Suns’ other four starters have all been more effective when playing with Baynes this season:

The Baynes Effect Phoenix Starters With Baynes Without Baynes Phoenix Starters With Baynes Without Baynes Ricky Rubio plus-8.9 plus-6.6 Devin Booker plus-7.9 minus-1.5 Kelly Oubre Jr. plus-7.6 minus-2.4 Dario Saric plus-8.9 plus-0.1

Ayton will have to be much better in Year 2 to fill the journeyman’s shoes. He has the physical tools to be an elite defender, but he doesn’t always use them effectively. Opposing players shot 62.8 percent at the rim against Ayton last season, compared with 53.9 percent against Baynes this season. The good news for the Suns is that Ayton played much better interior defense in his one game this season, blocking four shots in an opening-night win over the Kings. But no one has ever doubted his ability on that side of the floor—the question is whether he can be as consistent as Baynes.

Replacing Baynes on offense could be even harder. For one thing, the two play completely different roles. Ayton isn’t a secondary option. He averaged 16.3 points on 58.5 percent shooting as a rookie and was third on the team in touches (59) in the win against the Kings. He also operates in a different area of the court. Ayton shot only four 3s last season, although his smooth midrange jumper and decent touch from the free throw line (74.6 percent on 2.7 attempts per game last season) indicate that he could eventually extend his range. For now, he’s at his best when he can score over smaller defenders in the post, which means new Phoenix coach Monty Williams will have to restructure his offense to feature his young big man.

Ayton can dominate in those situations, but there is an opportunity cost to getting him the ball inside. Doing so takes the ball away from the Suns’ perimeter players while making it harder for them to attack the rim. So even if Ayton scores more than Baynes as an individual, it doesn’t necessarily mean that the offense as a whole will be more effective.

What Ayton will do is improve the Suns’ depth at center. Baynes is averaging only 24.3 minutes per game this season, which is still the most he’s ever played in his career, and he’s already suffered two different injuries—a hip contusion and a calf strain. His rough-and-tumble style may make it hard for him to stay healthy over the course of the season. And Phoenix hasn’t been nearly as good with Frank Kaminsky and Cheick Diallo at the 5.

The question when Ayton returns is how Williams will split up the minutes at the position. Baynes would become a part-time contributor if Ayton plays as much (30.7 minutes per game) as he did last season. The only way around that problem would be to play the two together—which isn’t as ridiculous as it might sound. Baynes can space the floor well enough for Ayton to score inside, while Ayton has the athletic ability to defend on the perimeter and allow Baynes to stay near the rim.

The problem is that it could ultimately hurt Ayton’s development by forcing him to learn a different position on defense. Phoenix will have a hard enough time turning him into a consistent rim protector even if he’s not spending half the game playing somewhere else. The Suns may have to live with Ayton taking his lumps and hope that he’s better for it over the long haul.

As for Sacramento, we may have buried the Kings too soon. After everyone wrote them off following their 0-5 start, they are now 8-7 over their past 15 games and only one game behind the Suns for the no. 8 seed. The wildest part about their turnaround is that it happened without either Bagley or De’Aaron Fox, who has missed the past 10 games with a sprained ankle. New Sacramento coach Luke Walton reinvented his team on the fly, slowing the pace of their games to a crawl after they played at one of the fastest tempos in the NBA last season.

Just like in Phoenix, there’s an unlikely hero at the center of it. Richaun Holmes, like Baynes, is a journeyman who has seized an unexpected chance to start this season. Playing for his third team in five years, Holmes has the best net rating (plus-5.6 in 507 minutes) of anyone in the Kings’ rotation. In fact, no one else is higher than plus-0.5.

The similarities go further. Both Baynes and Holmes are crafty players who play stout interior defense (Holmes is holding opposing players to just 52.0 percent shooting at the rim) and make the most of their limited opportunities on offense. Holmes uses speed and Baynes uses strength, but the results are the same. Holmes is an elite finisher (11.5 points per game on 65.7 percent shooting) who hardly ever touches the ball (32.7 touches per game). Instead of shooting 3s, he moves without the ball, dunks anything thrown near the rim, and displays incredible touch on his floater:

Walton has made a point of spacing the floor around Holmes, splitting the power forward minutes between Harrison Barnes, a combo forward, and Nemanja Bjelica, a stretch big man, which keeps four perimeter-oriented offensive players on the floor the entire game.

That approach wouldn’t work with Bagley, the opening-night starter at power forward. At 6-foot-11 and 240 pounds, he has a rare combination of size and speed that allows him to move on the perimeter like a much smaller player. But he wasn’t nearly as good an outside shooter or passer as a rookie as Bjelica and Barnes have been this season:

Kings Frontcourt’s Outside Shooting Player 3PA 3P% Assists Turnovers Player 3PA 3P% Assists Turnovers Barnes 4.1 37.7 2 1.4 Bjelica 4.2 40.8 2.5 1.7 Bagley 1.5 31.3 1 1.6

Moving Bagley into the starting lineup when he returns, much like Ayton with the Suns, would change the structure of the Kings offense. Holmes would be the biggest casualty. It would be hard for the two big men to play together, since defenses would pack the paint and dare them to shoot. The Knicks are the only team in the NBA who regularly start two nonshooting big men this season. And you never want to be on a list when it’s just you and the Knicks.

Sacramento was at least aware of this problem, which is why it gave a big contract (three years, $40 million) to another journeyman center (Dewayne Dedmon) in the offseason. Dedmon showed the ability to stretch the floor in Atlanta last season, but his outside shot has abandoned him in Sacramento. He’s shooting 22.2 percent from 3 on 2.4 attempts per game this season. The Kings went 0-4 with Dedmon in the starting lineup before pulling the plug. Playing Dedmon over Holmes to make Bagley comfortable would be taking one step forward and two steps backward.

The other way to space the floor around Bagley would be to move him to the 5. But he would have a hard time replacing Holmes on defense. He has many of the same issues as Ayton, except he doesn’t have the same massive frame to help make up for being out of position. Bagley allowed opposing players to shoot 60 percent at the rim last season.

The two young big men are caught in the horns of the same dilemma: They don’t protect the rim as well as most 5s or space the floor as well as most 4s. Until they address some of the holes in their games, they may not be the best options if their teams want to win. It doesn’t matter what Doncic and Young are doing at this point—Bagley and Ayton have enough to worry about on their own.