Motion tracking a cropped 4K footage

[GregGa]

First of all, I'm new to video editing so please excuse my illiteracy in this subject

I have a 4K footage of a subject erratically moving across the frame which I want to track in a 1080 crop. (My final clip will be cropped in about 50% and exported to 1080 resolution with a subject in a center being tracked)

Is it possible? If so, how is this technique called and how can I achieve this automatically without keying?

 

Thank you in advance!