If your manager is continuing to pile work on you, there will come a tipping point and tripping point where you will not be able to get everything done. There will be errors, missed deadlines, and rambling excuses. When that occurs, you will enter the ranks of the marginal employee.
There can be many positive reasons why your manager is giving you all of this extra work. He most likely views you as capable, industrious, and reliable.
Importantly, your manager is going to keep piling on work until you say something. This means that sooner or later, you are going to have to approach him. It makes far more sense to take a proactive approach rather than waiting until there are so many holes in the dike that you have run out of fingers and options.
You should approach your manager in a businesslike manner and let him know that your time is being stretched very thin, and you want to review your projects and priorities with him. It is possible that some of the work can be delegated, transferred, or eliminated simply as a result of this discussion.
There are two ways that your manager will find out that you are overloaded. One is that you meet with him and have a businesslike discussion, and the other is that your projects will start to fall apart. Which option do you prefer?
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