Aminu's agent, Raymond Brothers, confirmed the agreement Wednesday. It's a two-year contract for the veteran minimum of $2.1 million, with a player option on the second season.
Aminu has career averages of 6.5 points and 5.5 rebounds in four seasons with the Los Angeles Clippers and New Orleans. His best year was with the Pelicans in 2012-13, when he averaged career highs of 7.3 points and 7.7 rebounds.
The Mavericks signed Lewis to a one-year deal over the weekend but voided it when a physical showed that the 34-year-old needed surgery on his right knee.