A "medical redshirt" is really one instance of a hardship waiver (14.2.4). One of the requirements is:
Contemporaneous or other appropriate medical documentation, from a physician (a medical doctor) who administered care at the time of the injury or illness, that establishes the student-athlete’s inability to compete as a result of that injury or illness shall be submitted with any hardship-waiver request.
The injury or illness must also result in incapacity to compete for the remainder of the playing season;
This situation doesn't sound like it qualifies.