Welcome to the forum, Luise Sanz. This is a good observation: we often avoid using nouns to describe the action of verbs. However, they can be useful: The merchandise was delivered = the delivery of the merchandise. If I were you, I wouldn't worry too much about nominalization just yet. If you find yourself using a lot of abstract nouns ending in "___tion", then you would probably enliven your writing by turning those abstract nouns back into verbs. There is no reason to avoid the noun "worker". That is an everyday noun that people use all the time. Use it freely.
PS I just saw Loob's answer. I share her curiosity about what it is that concerns you. Some more examples would be very helpful to help people figure out how to help you avoid excessive nominalization.
Even if "the nominalization of verbs is often frowned upon" were true--I am more familiar with the "verbing" of nouns being met with criticism--it would not apply to words which have been in English for centuries, as worker has.