Everyday you call in sick, is a day closer some welfare mooch is to getting a real job.
Unemployment is high enough. We do not need more people looking for jobs.
If he loses his job and someone else gets it, the net number of people looking for the job is 0, since one person looking for a job is no longer looking and one person who was not previously looking for a job is. The unemployment rate will remain constant through this series of events.
In a very simplistic labor market (we aren't going to get into the complexities, just to keep the discussion grounded), the only way to change the unemployment rate is to change the number of jobs or the size of the labor force. If the job itself isn't eliminated in a labor force that is stagnant, then there will be no change in the number of people unemployed.

