Charania originally reported the Rockets planned to release Williams in a since-deleted tweet.
Williams, 23, averaged 1.3 points across four appearances for the Rockets this season.
His heaviest action came in the G League, where he lit it up to the tune of 19.4 points, 5.7 rebounds and 1.8 steals per game for the Rio Grande Valley Vipers.
Now in his 17th season, Johnson is averaging 7.3 points and 3.3 rebounds per game while shooting 42.0 percent from the field and 27.4 percent from three-point range.
Those figures are rather inefficient by Johnson's standards since he's a 37.2 percent three-point shooter for his career, but they stand to balloon in Mike D'Antoni's uptempo system that affords marksmen plenty of space to let fly.