If you feel you are left out of important meetings that you would normally attend, then that could be a sign that you are not needed anymore.
2) Access Level Reduced:
Your access to information within the company has been reduced. It is hard for you to get to data with no obvious reason.
3) Reduced Responsibilities:
Your level of responsibilities and tasks is significantly reduced. The majority of your work has been given to someone else and you are left with minimal duties.
4) Reduced Power:
Suddenly you lose control over many issues related to your scope of work. Nobody listens to you anymore and you are unable to take decisions as usual.
Your employers decide suddenly that you need a vacation! That means give us time and space to find a replacement.
6) The Magnificent Assistant:
The company hires an assistant to you with similar qualifications. It is only a short time before he/she learns everything needed and throw you out of the window.
7) The New Boss:
The company appoints someone to manage you and monitor your work. It is not because they want to see if you are eligible for a bonus, but because you are terrible at what you do (at least in their minds).
Your opinion suddenly doesn't matter and nobody is interested in what you have to say. Your coworkers start to take you lightly and even try to avoid you. That is good indication that you are not wanted anymore.
9) Mistakes, No Problem:
Your errors are lightly taken. You commit a mistake and your manager barely comments on that. You arrive late to work and nobody even asks you where you have been. This is your manager's way of telling you:"It doesn't matter anymore".
10) Out of the Loop:
You are not receiving announcements anymore. You get to know things by chance or through your friends at work.
11) Formal Communication:
If you notice that all communication between you and your superiors is suddenly by emails rather than verbally, then this could be a sign that something is going on. Your superiors are trying to document everything to prove that you are not working as you should be.