The Lions will have another quarterback on the practice field when they return from their bye this week.
Boyle can practice for the next 21 days before the window to activate him will close. He can be added to the active roster at any point in that span.
Boyle appeared in 11 games for the Packers over the last two seasons and completed three of the four passes he threw in those appearances. If activated, he’d join David Blough as backups to Jared Goff on the 53-man roster.