49ers sign Christian Ponder, place Thad Lewis on injured reserve

SANTA CLARA, Calif. -- After a pair of injuries left them thin at quarterback, the San Francisco 49ers moved to add some depth Tuesday, signing veteran Christian Ponder.

The team announced that it signed Ponder to a one-year deal. Ponder replaces Thad Lewis, the quarterback who suffered a torn left ACLin Sunday's preseason opener, on the roster. The 49ers officially added Lewis to the injured reserve list, ending his season.

After the news of Lewis' injury broke Monday, Niners coach Chip Kelly and quarterbacks coach Ryan Day said the team would explore options to bring in another arm.

"We just lost Thad, which is disappointing for us," Day said. "We really felt like we were creating depth at the position and then we lose Thad, so it's an obstacle we've got to overcome. But that's part of coaching in the NFL. Nobody else cares, so although it bothers us, we have to come up with a new plan moving forward."

That plan led them to Ponder, the former No. 12 overall pick of the Minnesota Vikings in the 2011 NFL draft. Ponder joins Blaine Gabbert and Colin Kaepernick as quarterbacks on the roster from that draft.

In Minnesota, Ponder played in 38 games with 36 starts, throwing for 6,658 yards, 38 touchdowns and 36 interceptions in four seasons. He had brief stops with Oakland and Denver last year but did not appear in a game.

Adding Ponder also provides the Niners with needed practice depth, as Kaepernick has been dealing with tightness in his right shoulder. Kaepernick has not thrown a football since last Wednesday's practice at Kezar Stadium.

Kelly has said the issue isn't believed to be long-term; Kaepernick's status remains day-to-day. Ponder joins Gabbert and rookie Jeff Driskel as the team's healthy quarterbacks.

The 49ers were scheduled to travel to Denver on Tuesday afternoon for a pair of joint practices with the Broncos on Wednesday and Thursday before Saturday night's second exhibition game.