According to a report from Andrew Mason, senior digital reporter for the Denver Broncos, Peyton Manning will be held out a third week as he recovers from a torn plantar fascia.

That means he’ll miss a Dec. 6 trip to San Diego to play the currently 2-8 Chargers. San Diego plays at Jacksonville this week after a 33-3 home loss to the Kansas City Chiefs, who are now 5-5 and three games back of the Broncos in the AFC West.

According to Mason, Manning will “spend at least the next week in a walking cast” and resume additional rehabilitation after that time.

The extended recovery time means Trevor Siemian will be Denver’s only option behind Brock Osweiler at quarterback, at least for the time being.

Siemian is a rookie out of Northwestern. Head coach Gary Kubiak called the seventh-round pick “a very confident kid” when he made the 53-man roster this summer. But with the Chiefs suddenly nipping at their heels and juggernauts in New England, Pittsburgh and Cincinnati on the schedule still, Kubiak must not be feeling too confident.

Mason also reports that the team plans to work out former Vikings quarterback Christian Ponder.

After four years (2011-14) with the Minnesota Vikings, compiling a record of 14-21-1, Ponder failed to make the Oakland Raiders roster this season as a backup to Derek Carr. Ponder has a lifetime completion percentage of 59.8 and has passed for 6,658 yards, 38 touchdowns and 36 interceptions in 38 games (36 starts). He started 26 games in his first two seasons in Minnesota, but just nine in the third and just one in 2014.

On Monday, Kubiak called the quarterback situation “week-to-week.” With Tuesday’s announcement, it appears some longer-term planning is already underway.