The Knicks waived Morris on Saturday, Tim Bontemps of ESPN.com reports.
Marcus Morris will join the Knicks on a one-year deal, Shams Charania of The Athletic reports.
Morris won't start Sunday's Game 7 against the Magic, Serena Winters of Bally Sports Cleveland reports.
Morris is in the starting five for Friday's Game 6 agains the Magic.
Morris finished Tuesday's 104-103 victory over Orlando in Game 5 of the first round of the Eastern Conference playoffs with 12 points (4-9 FG, 2-5 3Pt, 2-2 FT), three rebounds and one assist in 26 minutes.
The Cavaliers are planning to sign Morris to a rest-of-season contract Thursday, Chris Fedor of The Cleveland Plain Dealer reports.
Morris became a free agent Thursday after his 10-day contract with the Cavaliers expired, Keith Smith of Spotrac.com reports.
Morris provided 11 points (4-10 FG, 1-5 3Pt, 2-2 FT), seven rebounds and one assist over 26 minutes during Friday's 104-91 loss to the Timberwolves.
Morris contributed 14 points (5-7 FG, 4-5 3Pt) and four rebounds across 20 minutes during Monday's 108-103 victory over the Pacers.
Morris is active for Monday's game against Indiana, Chris Fedor of The Cleveland Plain Dealer reports.