For example, Wang and Zimmermann are writing a research paper together. In their paper, they want to refer to Zimmermann's previous work (possibly with other coauthors).

Should they write "In the second author's previous work, ..."
or "In Zimmerman's previous work,..."?

The second option is not making clear that they are referring to one of the present coauthors, since there are so many Zimmermann's in the world. Perhaps, the reader should figure that out by referring to the References list?