When you first started your job, your boss was supportive, encouraging, and eager to help you grow your career. But lately, your relationship seems strained, and your boss will barely give you the time of day. If this sounds like you, chances are it's because your manager sees you as a threat. Here are a few telltale signs that should raise a red flag -- and prompt you to take action.

1. You're excluded from meetings you should be a part of

Many of us detest meetings and would do anything to avoid them. But being excluded from important meetings with key players can become a major career setback, and if your boss is being stingy with those invites, it means he or she clearly doesn't want you there. Maybe your manager is afraid of being shown up. Or maybe your boss just wants you kept in the dark. Either way, it's not a good sign.

Man in suit looking critically at a second professional male who's looking down.

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2. You're constantly being criticized

It's one thing for your manager to provide constructive criticism designed to help you do better on the job. But if your boss has nothing but negative feedback to share, and that feedback isn't concrete enough for you to act on, then it's a sign he or she just plain isn't interested in being supportive and probably wants you out.

3. Your days are suddenly filled with busy work

Even high-level executives see their share of grunt work from time to time. But if you come to find that your days are filled with meaningless projects instead of the high-profile ones you used to get, it's probably because your manager doesn't want you working on anything big. And that will not only lead you to a frustrating place, but also hinder your career in a very big way.

4. Your boss no longer asks for your input or opinion

Most managers don't operate in a bubble. Rather, they solicit their employees' feedback and take their input into consideration. But if your boss no longer asks for your input, or, worse yet, seeks everybody else's opinion but yours, it's a surefire sign that he or she wants you gone -- even if you did nothing to deserve that sort of treatment.

5. Your boss stops being available to you

Some managers are busy by nature and don't necessarily have time for weekly heart-to-hearts with employees. But if your boss used to make time for you and suddenly can't seem to carve out five minutes for a quick conversation, it's probably because he or she is secretly hoping you'll quit.

What to do when your boss sees you as a threat

Having a manager who feels threatened by you is a tough spot to be in. You can try talking things out with your boss, but chances are, that'll end up being an overwhelmingly awkward and unproductive conversation. If your boss does feel threatened by you, he or she will be to loathe to admit it. And once you bring it up, he or she will probably get defensive and treat you even more poorly going forward.

Therefore, your best bet might be to talk to your manager and/or human resources department about switching teams. If you pitch that suggestion as a means of furthering your career, as opposed to escaping a bad boss, your manager might be quick to agree, and you can escape the situation with your professionalism intact. If that doesn't work, you might come out and say that you feel you're being treated poorly and would like an opportunity to stay with the company under someone else's management.

If moving to another team isn't an option, you might consider switching companies altogether, and starting over with a clean slate. Frustrating as it may be to have to leave your job because of your manager's sudden ill feelings toward you, it's a better bet than letting a threatened boss derail your career.

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