49ers elevate two players to face Saints, sign Curtis Robinson to 53-man roster

The 49ers have one available quarterback on their 53-man roster, so they made a move Saturday to get a backup for Mac Jones in uniform.San Francisco elevated quarterback Adrian Martinez from the practice squad to serve as the team’s No. 2 with Brock Purdy ruled out with a toe injury. The 49ers also elevated tight end Brayden Willis, who will fill the third-string role behind now-starter Luke Farrell and backup Jake Tonges with George Kittle sidelined by a hamstring injury.Martinez will wear No. 4 and suit up as the 49ers’ backup for their Week 2 game Sunday against the New Orleans Saints.The 49ers also promoted linebacker Curtis Robinson, who was on the practice squad, to the 53-man roster and waived defensive end Robert Beal Jr. to open a spot.The 49ers go into the game with an uncertain situation at wide receiver. The 49ers did not elevate receiver Russell Gage from the practice squad.Jauan Jennings is listed as questionable with a shoulder injury. It appears as if Jennings will be available, but if the 49ers decide late to deactivate him, rookie Jordan Watkins would be in line to make his NFL debut.The 49ers’ other wide receivers are Ricky Pearsall, Marquez...