49ers announce key roster moves ahead of TNF showdown with Rams

The San Francisco 49ers announced several roster updates ahead of the Thursday Night Football game against the Los Angeles Rams.

Promoted to the active roster from the practice squad:

• QB Adrian Martinez

Martinez joins the active roster after the 49ers ruled out starting quarterback Brock Purdy against the Rams. Mac Jones is set to make his third start of the season, with Martinez serving as his backup.

Activated from the practice squad (standard elevations):

• DL Trevis Gipson
• WR Malik Turner

Turner bolsters a receiving corps that will face the Rams without Ricky Pearsall (knee) and Jauan Jennings (ankle, rib). Both were ruled out this week.

Waived:

• DL Jordan Jefferson

Additionally, the team has signed cornerback Derrick Canteen to the practice squad. Canteen (5-10, 193) originally joined the 49ers practice squad on August 27, and was released on September 24 before being re-signed.