CJ McCollum suffered a L3 vertebral transverse process fracture (non-displaced) last Thursday, sources told NBC Sports Northwest.
McCollum, who shot 2-14 from the field on Tuesday against the Mavs, has played three games with the injury.
McCollum hit two free throws late in the Blazers' win against the Mavs.
"One thing that is a part of our relationship and something that makes us have so much belief in each other is -- he knows that I have unwavering confidence [in him] and I know the same thing about him. I know his heart. I know his toughness. I know who he is as a man," said Damian Lillard about McCollum after the game.