is not promoting, discrimination?

Can an employee claim discrimination if he is
past over for promotions over the course of a ten year period. The persons chosen for promotion all have considerably less time on the job. All employees are in the same Job and are all equally qualified. The employee in question has excellent reviews. The only reason given for being passed up for promotion is, The employee in question was told he had a bad attitude. Is there anything that can be done?
Thank you

Well how about....Working on his BAD attitude.

What discrimination is there, the employer seemed to be quite clear why he has not been promoted.