As their relationship with Kristaps Porzingis sits on rocky terrain, the Knicks made a curious decision to not renew the contract of popular assistant Josh Longstaff, the Daily News has learned.

Longstaff was one of the few remaining holdovers of Derek Fisher’s original staff, but more importantly he developed a connection with multiple current players — most notably Porzingis — and went overseas last year to help train the Latvian forward. Porzingis had even requested that Longstaff serve as an assistant on his Latvian national team this summer for the European championships, as The News previously reported.

The reasons for cutting ties with Longstaff are unclear, but a member of the organization called him the hardest worker on the staff. It’s worth noting the Knicks are moving forward with a heavy focus on the triangle at all levels of the organization, including Longstaff’s former role in player development.

Longstaff, 34, assisted last season in the improvement of young rotation players, with Willy Hernangomez and Ron Baker taking large and unexpected leaps. In seasons prior, he did the same for Lance Thomas and Langston Galloway. Player development was one of the few bright spots in Phil Jackson’s tenure.