Several people have emailed me to report that there's a new player wearing Paul Hornung's #5.
This is Omarius Hines, an undrafted free agent WR out of Florida. He previously signed with the Baltimore Ravens on April 27, and was waived on July 22. The Packers picked him up on July 29.
Again, wide receivers are not eligible to wear single-digits (unless there has been an unannounced change in the rules), so even if Hines makes the roster I'd expect him in a different number by the beginning of the season.