Knehr (elbow) was transferred Tuesday from the 15-day injured list to the 60-day injured list.
The move frees up a 40-man roster spot for catcher Luis Campusano, who was activated from the 60-day injured list after recovering from May surgery to repair a torn thumb ligament. Knehr remains sidelined indefinitely with a right elbow strain and won't be eligible for activation until at least late August.