http://www.coloradorapids.com/news/2014/03/rapids-welcome-neeskens-and-piermayr-trial John Neeskens Right/center back + holding mid, has U.S. passport (so presumably wouldn't be an international) Thomas Piermayr Left back/mid, international
You're right, its his son that's on trial (who apparently doesn't have a Wikipedia entry) but I just linked to the first one I found. Fixed.
I don't know how I missed that line that says "as trialists." I guess big soccer has finally made me go cross eyed. It was bound to happen.