yes, but not easily. You will have to dig into the code and make some changes.
Excerpts are dynamically built, so there is no way to look at a switch and see if you are dealing with an excerpt, this added to the fact that you can control how many excerpts are on the page and that the dynamic building of the excerpt comes after the byline has been created is the reason you will have to dig into the code and modify the code to do this.
The code to create the excerpt is in functions.php if you decide to go forward. If you do, please share your solution for others.