The initial MRI on Ryan Williams' right knee was "clean," Cardinals coach Bruce Arians told the Arizona Republic.

“Ryan’s going to get a second opinion,” Arians said. “We’ll see when he comes back. It just flared up. There’s no injury; the MRI’s clean.”

Williams tore the patella tendon in his right knee nearly two years ago. Arians said the 23-year-old running back, who watched Sunday's practice with the knee wrapped in an ice pack, looked good in earlier practices.

“I was kind of surprised it flared up," Arians said.