The Hawks had initially stated Tuesday that Johnson would be listed as doubtful for Wednesday's game at New York because of tendinitis in his left knee, an injury that forced him to leave Monday's contest against Chicago.
However, an updated release later Tuesday said Johnson would be returning to Atlanta for an MRI exam. He will also sit out Thursday's home game against Orlando.
Johnson, selected to the All-Star Game as a reserve for the Eastern Conference, is Atlanta's leading scorer at 17.6 points per game.
The Hawks expect to have forward Marvin Williams back for Wednesday's game against the Knicks after he missed the 90-79 loss to the Bulls to attend the funeral of a family member. He is averaging 9.6 points and 5.4 rebounds in 28 games this season.