The Oklahoma City Thunder are signing former New York Knicks big man Isaiah Hartenstein to a three-year, $87-million deal, sources told ESPN's Adrian Wojnarowski.

Hartenstein broke out this past season, averaging 7.8 points and a career-high 8.3 rebounds per game, starting in 49 of his 75 appearances. He excelled during the Knicks' playoff run in a full-time starting role, putting up 8.5 points, 7.8 boards, and 3.5 assists.

The 7-foot German American finished third in the NBA in defensive box plus-minus and averaged 1.2 steals and 1.1 blocks per game.

Hartenstein's rebounding and defensive prowess will join forces with elite shot-blocker Chet Holmgren in the Thunder's frontcourt.

Oklahoma City finished 27th in rebounds per game and allowed the second-most offensive rebounds to its opponents.