After Sunday night’s loss to the Seahawks, 49ers coach Jim Harbaugh said that the preliminary assessment of linebacker NaVorro Bowman’s knee injury revealed a suspected ACL injury.

Per a league source, the team fears both an ACL and MCL injury. An MRI, which has not yet been conducted, will reveal the full extent of the damage.

While mild to moderate MCL injuries can heal without surgery, an MCL injury could delay Bowman’s timetable for surgery, if the decision is made to allow the MCL to heal before repairing a possible torn ACL. Patriots tight end Rob Gronkowski waited one month and one day to have ACL surgery because of an MCL injury that needed to heal.