The Celtics pulled a difficult trigger in trading Robert Williams III this offseason which is already sparking skepticism surrounding Boston’s plan to fill the defensive void now in place.

Williams was Boston’s defensive anchor in the interior, blossoming as a block machine with a jaw-dropping vertical. Although the impact wasn’t nearly the same on the offensive end, losing Williams removes the first (Marcus Smart) and second (Williams) most pivotal pieces in terms of defense for the Celtics.

And NBA legend Vince Carter doesn’t see it working out.

“Losing Robert Williams is huge,” Carter explained on ESPN’s “The VC Show.” “Everybody’s like, ‘He gets injured a lot.’ Yes, got to get healthy. Yes, totally agree. But his presence defensively is paramount to what they’re trying to do because when you think about it, you’re dealing with Giannis (Antetokounmpo) who’s very good in the post, you’re dealing with (Joel) Embiid who’s very good in the post. … They’re not able to guard those guys.”

Harsh, but fair.

Carter also mentioned that even if the Celtics escape the Eastern Conference, there are plenty of interior threats — Nikola Jokic and Anthony Davis — which Boston isn’t equipped to handle in his opinion.

Just two years ago Williams finished second in the lead NBA for blocks per game (2.2).

Obviously, replacing what Williams brings to the table on a night-to-night basis isn’t easy. In fact, addressing that loss with a more established defender who also brings size would be ideal, and there’s still plenty of time before the playoffs roll around to do so.

Maybe by then, Carter’s critiques will truly be felt by Boston.