on july 26, 2017, williams re-signed with the suns to a multi-year contract. on september 25, 2017, he was ruled out for six months after undergoing a meniscus repair of his right knee. on march 15, 2018, he was assigned to the northern arizona suns. he was recalled on march 16, reassigned on march 20, and recalled again on march 25. on march 26, he made his season debut for phoenix against the boston celtics. in 16 minutes off the bench, he recorded three points and five rebounds in a 102–94 loss.