The move Wednesday comes as the winless Panthers are still waiting for right tackle Jeff Otah to get healthy following knee surgery. Otah hasn't played or practiced this season, and the Panthers have struggled to open running lanes and protect the quarterback.
The 27-year-old Morris was the Raiders' seventh-round pick in 2006. He started 10 games last year but was let go in final cuts earlier this month.
The Panthers had an open roster spot after releasing defensive tackle Louis Leonard on Tuesday.