The Warriors said Evans was placed in the NBA's concussion protocol.
Evans was taken to a local hospital on Tuesday night after leaving the 124-97 loss to Dallas.
The play occurred with 4:38 remaining in the second quarter as both Evans and Powell went up to the rim to grab the ball. Powell's right elbow inadvertently came down on Evans' face, and Evans fell to the floor.
The second-year guard stayed on the floor for several minutes while being checked out by the Warriors medical staff, but appeared woozy. He eventually made his way off the floor with the help of members of the Warriors' staff.
Information from ESPN's Nick Friedell was used in this report.