Johnson is questionable for Thursday's game against the Rockets due to left calf tightness.
After logging 33 minutes during Wednesday's 117-106 win over the Celtics, the star forward is in jeopardy of sitting out the second leg of this back-to-back. With Onyeka Okongwu (face) already ruled out, the Hawks could need Corey Kispert and Luke Kennard to play significant minutes in the frontcourt Thursday.