Disabled soldiers were retained and reassigned, not discharged. [fact]
After being treated for their wounds, the sakat (lit., the fallen), as the disabled were referred to, were checked by the hakimbaşɩ, the chief doctor of the hospital. Those who were found not to be completely disabled and who were still capable of bearing arms would be designated as yarɩm sakat, i.e. half-disabled, and would be retained in the army. When enough of those half-disabled soldiers had been so designated they would be grouped together to form a battalion and a sakat officer would be appointed as their commander. … When the army had no need for them but they could still be used for other jobs, they were not released or sent back to their villages, but were formed in companies, had a "half-disabled" officer appointed as a commander and assigned to perform various tasks. These might be to assist in guard duties, in repairing and fortifying buildings, or as servants in military hospitals.
Khaled Fahmy, All the Pasha_s Men_ Mehmed…, loc. 1340