The weakest link in any team-building plan, tanking or not, is how injuries can happen at any point, any time. NBA teams proportionally depend more on their best players than any other major team sport, with fewer players on the court carrying proportionally heavier burdens. So when one of your prospective franchise players appears to be an injury risk, plans must be made accordingly.
Nerlens Noel played in 5 out of a possible 11 summer league games. And in those five games, Noel came up lame in three of them. He suffered from cramps and twisted an ankle multiple times. While maybe a result of fatigue from playing more in 11 days than he had in 18 months, it still could not be considered encouraging, unlike his on-court contributions.
(He also had a cold for his final game, which didn't help matters. He lacked anything resembling energy - lethargic might best describe what he looked like, though since he was in Las Vegas "morning after" might work as a description too.)
Why did he appear injured so often? The answer appears pretty simple. Most attribute the injury risk to his narrow, light lower body. He doesn't have much weight behind him. He can get moved around easily. He has long strides. He takes awkward steps in the post. All are important, but the most pressing and distressing issue to me is that he does a lot of athletic things that can put him in awkward positions in the air.
Most bigs have issues with their lower extremities because those extremities have to support running on lots of weight. The large weight and frame puts pressure on the feet and knees. Noel doesn't really seem to have that problem - he's so impossibly light on his feet for a person his height that he almost seems more likely to suffer from issues that tend to happen to perimeter players who spend time off the ground.
His ACL injury - which I won't link to, because GAH THE HORROR - occurred because he landed poorly while attempting to run and block a shot in transition. Trying to send the opponent into a walk of shame left him unable to walk. No stanchion was involved, but Noel showed the same super-athletic, how-can-he-do-that type of awe-inspiring athleticism Paul George showed off before his devastating injury.
Being able to alter so many shots gives him more chances to land awkwardly or on another person's foot, giving him more chances to alter the game play (and be very, very good) and also more chances to injure himself. It's easier to twist an ankle when you move up and down the court like a leaping pogo stick for 30 minutes than when you move up and down the court like Henry Sims.
Optimally, Noel would go for blocks on shots he has a good chance of blocking and just walk away from those with lower odds. Realistically, he'll learn as he goes along. During the summer leagues, Noel tended to go after everything. Opponents basically gave up in going at him after a while - note: repeat after me, "rim protection is at a premium in this league" - so that worked well for the Summer Sixers. But in going for everything, he put himself in poor positioning for potential rebounds.
Over time, Noel should learn to go for fewer blocks, risking less and producing more.
The more minutes = more injury risk equation applies to almost any player, but based off Noel's history and what you can reasonably project him to be, the baseline risk with him appears significantly higher than the average player. It's a risk the Sixers are going to have to endure to get a great player, and it's a risk they'll do their best to mitigate as well.
One way the Sixers have already experimented with was giving him no back-to-back games during summer league. Especially early in the season, I would expect this to continue. He may not be a healthy scratch 21 times this season, but smart money says he should sit at least a few of them as he builds the stamina to play more games. Other health-conscious options include playing him more minutes while in foul trouble - learning to defend without fouling should reduce the number of high-risk defensive plays - and minutes restrictions. The balance will be delicate but necessary, and with my fingers crossed, I'm looking forward to what the Sixers plan to do.