The veteran power forward agreed to leave Toronto and stay within the Atlantic Division on Wednesday. The person spoke to The Associated Press on condition of anonymity because no deals can be signed yet.
Johnson averaged 9.3 points and 6.1 rebounds for the Atlantic champions last season, his sixth in Toronto. The 6-foot-9 Johnson began his career in Detroit, where he was a second-round pick in 2005.
AP Basketball Jon Krawczynski contributed to this report.