The team announced the move Monday but did not disclose terms.
The 6-foot-9 Amundson has played for 10 teams. He appeared in 70 games over the last two seasons with New York. He averaged 1.8 points and 1.7 rebounds over seven minutes a game last season.
Amundson has appeared in 428 games over 10 seasons with Utah, Philadelphia, Phoenix, Golden State, Indiana, Minnesota, Chicago, New Orleans, Cleveland and New York.
He was acquired from Cleveland as part of a three-team deal in January 2015.