The news was first reported by the Detroit Free Press.
Redfern's injury came after he dropped a snap on his second career punt in the first half. He then chose to try and run the ball, getting 10 yards out of the end zone before being tackled by Ifeanyi Momah as he was running along the sideline. Redfern's first punt went 50 yards.
The Lions immediately brought him to the training table and then carted him back to the locker room.
Detroit will be auditioning punters this week to find a replacement for Redfern at least until Week 7, when starting punter Sam Martin is eligible to come off the non-football injury list. Redfern made the Lions after the franchise placed Martin on the NFI list on cut-down day.
The Free Press is reporting among the punters the team is bringing in for workouts are former Miami punter Matt Darr and Drew Butler, who was a camp leg for the Lions in 2014.
Lions coach Jim Caldwell said Monday he didn't think fitting in to the team on short notice was more difficult for a punter than other positions -- including offensive line, secondary and quarterback.
"I can think there are a lot that are a lot more difficult," Caldwell said. "But it's just a matter of a guy doing his job, plain and simple. There are going to be some things he's not going to know right away. We can limit that but if he does his main job, that's what counts."
Caldwell also declined -- again -- to explain how Martin was injured this summer. Caldwell had initially said Martin would be back during training camp, but he never participated in practice. When asked if he was disappointed in Martin for getting hurt, Caldwell didn't answer the question and walked off the podium.