I am not clear of a named number of sick days in company policies.
If you are sick, you take the day off. If you are feeling better, but may be contagious, and your work allows, you may choose to log in and do work.
If you have performance issues, you have performance issues. A manager knows that. Sure you track sick days. If there is a chronic pattern of being off on Mondays after partying all weekend, then, hey, you as a manager address it as impacting work performance, but, typically, it would be through performance related items.
So, I am all for people takign time off for when sick.