"If he's healthy enough to play, he'll play," said Phillips, who added that Williams could play against Kansas City even if he doesn't practice this week.
Williams, who suffered cartilage damage to three ribs during last week's loss to the Denver Broncos, said Wednesday that he looks forward to playing this weekend.
"It's going to be my call," said Williams, who joined his teammates on the practice field but did not wear a helmet or any pads. "It's my body, nobody else's. I've got to be smart about this thing. If I can go, I'm going to go."
Tim MacMahon covers the Cowboys for ESPNDallas.com.