Ryan Mathews, Keenan Allen out vs. SF

The Chargers last visited Levi’s Stadium in August.

Ryan Mathews and Danny Woodhead were at running back, Keenan Allen at wide receiver. In 2013, the trio together accounted for 85.7 percent of the team’s running game and 42.5 percent of the receiving game.

On Saturday night, the Chargers will return to the stadium.

None of the three will play.

San Diego announced its injury report Friday afternoon. As expected, Mathews (ankle) and Allen (collarbone, ankle) were listed as out. Woodhead has been sidelined since a September leg injury ended his season. Quarterback Philip Rivers will lead what’s left of his skill-position players against the 49ers, a team they faced at the same site in the preseason.

The Chargers (8-6) have lost their past two games, scoring one offensive touchdown in each.

At least they have Rivers.

He is listed as probable after not practicing Wednesday due to a back and rib injury. It was his first missed practice since the 2007 postseason. The Chargers said that Rivers was a full participant in their Thursday and Friday sessions.

Defensive end Corey Liuget (ankle) and tight end Ladarius Green (ankle, concussion) are considered questionable. They also were full participants on Friday.

Saturday will be the ninth game Mathews has missed this year.

He was sidelined seven games following a Week 2 knee sprain. Now, after a nasty Dec. 7 ankle injury suffered incidentally when a Patriots linebacker tackled him from behind, it appears likely he will miss the remainder of the regular season.

Mathews is in the final year of his rookie contract. He’s scheduled to become an unrestricted free agent on March 10.

Allen previously has never missed an NFL game due to injury. Coach Mike McCoy officially ruled him out earlier in the week.