In order to successfully sue your employer for disability discrimination you will need to show more than an adverse employment action resulting from an occupational injury.  You must also show you were treated differently by being singled out for disadvantageous treatment because of your injury.

An employer is not guilty of retaliatory discrimination by failing to ‘reemploy’ unqualified employees for whom positions are no longer available.  And an employer may be justified in terminating an employee if at the time of termination the employer reasonably believes that returning the employee to his position would endanger the employee or others.

An employer’s refusal to reinstate an injured worker to an available position may be justified as a business necessity if the employer reasonably believes that the employee is unable to perform the job without undue risk of reinjury.

If business realities compel the employer to replace an employee on workers’ compensation disability leave, the employer may refuse to reinstate the employee assuming the position remains unavailable.

Also if you lose your job following a job related injury you must engage in what is known as an interactive process with your employer in order to find a reasonable accommodation for your disability.  The employer must try to reaonsable accommodate your disability if such accommodation is available.