Summary
Poeltl's best skill is his offensive rebounding, as he has consistently been in the top of the league in offensive rebounding rate, per Cleaning the Glass. He also finishes well at the rim, as he is a skilled big with good hands. On defense, Poeltl uses his size and positioning to be a solid rim protector. However, his lack of athleticism makes it difficult for him to defend in space and in the pick-and-roll, something that can be taken advantage of by offenses, especially in the playoffs.
 
Despite Poeltl showing some promise early in his career, I would be skeptical giving him big money, as centers in his mold can usually be had for cheap. With restricted free agency muddying the waters further, Poeltl's likely best shot at a big contract is convincing the Spurs that he is their center of the future.
 
Cap Considerations
Poeltl will be a restricted free agent with a $11.3 million cap hold and a likely $5.1 million Qualifying Offer. Poeltl is one of those free agents for which I could see the QO actually coming into play. If the Spurs play hardball with Poeltl and let him test restricted free agency, he could struggle if the center market lacks demand, and he could end up settling for the QO with the Spurs.
 
If Demar Derozan opts out and leaves, the Spurs could potentially have a significant amount of cap space. And having that space may cause the Spurs to rescind Poeltl's QO and renounce him in order to remove his cap hold and free up cap space. Doing so would make Poeltl an unrestricted free agent, and the Spurs would no longer have his Bird rights. It should also be noted that the Spurs can rescind his QO without removing his cap hold, thus making him an unrestricted free agent but keeping his Bird rights to potentially re-sign him.
 
For other teams, the ability to get Poeltl will likely depend on if he is a restricted or unrestricted free agent. If he is restricted, teams might worry that the only way to pry him away from San Antonio would be to significantly overpay him. Poeltl's starting salary will likely fit within the full $9.3 million Non-Taxpayer Mid-Level Exception, so even teams without cap space could potentially target him.