I was fire from work for calling in after a work related injury, I am already suing workmans comp. Can I sue my employer for firingme if I can prove

This is always a difficult situation. Some states prohibit retaliatory discharge by an employer against an employee who has availed himself of workers comp. These are extremely difficult cases to prove, because the "default setting" is that employment is on an at-will basis; that means that the employee may generally be terminated at any time for any reason or no reason at all.