The Saints placed Silver (undisclosed) on the active/PUP list Tuesday, Katherine Terrell of ESPN.com reports.
The nature and severity of Silver's injury is unclear, but he'll be eligible to return to practice at any time once he's fully healthy. He signed with the Saints as an undrafted free agent in late April following a four-year college career. Silver logged 20 total tackles, including 1.0 sacks, across 12 games with USC last year.