There are many things that could be valid grounds for termination, but your workers’ compensation status would not be one of them. If your employer were to tell you that you were being fired because you were receiving benefits, they would probably be violating your rights under Missouri law.
Even if your boss were to give a different reason for firing you — other than your workers’ comp, that is — there could be more to the story. Looking into the situation surrounding the incident could help you in multiple ways, by illuminating what you did wrong or revealing the fact that your company is trying to illegally fire you, for example.
Any employment change that came soon after an injury would probably be something to which you should pay careful attention. Depending on your contract with your employer, each of you might have certain privileges when it comes to continuing or terminating your professional relationship. However, none of these contractual terms would override workers’ protection laws.
The Missouri Department of Labor & Industrial Relations website has a relatively complete resource for dealing with a professional injury, the work repercussions section of which states that you could file a civil suit against your employer if you experienced a discriminatory termination.
It would be natural for you to want to wait until things calm down handle an employment issue, such as retaliatory or unjust termination, especially if you are already juggling medical appointments, workers’ comp issues and a looming job search. However, the quality of evidence in your case could degrade over time, making it more difficult to prove employer wrongdoing. Of course, each situation is different, so please only look at this as basic information. It is not intended as legal advice.