The Knicks pulled a shocker Thursday morning with general manager Glen Grunwald apparently being relieved of his position.
ESPN's Marc Stein originally reported the move on Twitter.
Grunwald took over as interim general manager in July 2011 when Donnie Walsh decided to leave the franchise and then took over permanently in April 2012. Grunwald had originally joined the organization in September 2006 as assistant general manager under Isiah Thomas.
Owner James Dolan announced in a statement Grunwald has been reassigned within the organization.
Steve Mills, who previously served as president of Madison Square Garden, will replace Grunwald. Mills worked in the league office from 1983 to 1999, when he joined MSG. He left his position as president of MSG in 2009.
"I am pleased to be able to welcome Steve back to the Knicks," Dolan said in a statement. "He is a well-respected sports executive with a strong background in basketball, as well as a familiarity with NBA operations and our company."
"I want to thank Jim for this opportunity to return to the Knicks in this important position," Mills said in a release by the team.
There had been reports earlier this summer Mills was favored to take over as NBA players' association executive director after the ouster of Billy Hunter. The position remains unfilled.
The move appears to come as a complete surprise. Grunwald had not been criticized and had worked to improve the team in the offseason.
Grunwald spoke about the additions of Metta World Peace and Andrea Bargnani, which he appeared to be heavily involved in. He was also integral in the acquisition of center Tyson Chandler and guard J.R. Smith. He was also involved in re-signing Smith.
The Knicks were 54-28 last season and won the Atlantic Division. They won their first playoff series since 1999-2000 over the Celtics, but lost in the second round to the Pacers in underwhelming fashion.
Follow Metro New York Sports Editor Mark Osborne on Twitter @MetroNYSports.