Power Rankings: No. 12 San Diego

A weekly examination of the Chargers' ESPN.com Power Ranking:

Preseason ranking: 23 | Last Week: 15 | ESPN.com Power Ranking since 2002

With the team’s first three-game winning streak of the season, the San Diego Chargers climbed three more spots to No. 12 in ESPN.com’s weekly NFL Power Rankings.

At 8-7, the Chargers are ranked ahead of the other three teams battling for the final AFC wild-card spot: Baltimore (No. 14), Miami (16) and Pittsburgh (18).

The Chargers have won four of their past five games, and are 10-4 in December or later in the last three seasons. However, San Diego will deal with some question marks this week, mainly workhorse running back Ryan Mathews, who's battling an ankle injury.

San Diego coach Mike McCoy said Mathews is expected to play Sunday, although he likely will not practice much this week. In the past three games, all victories for the Chargers, Mathews has totaled 329 rushing yards and three touchdowns.