What does San Diego have to do with it?
They've already been eliminated.
The Chiefs need a win over the Bengals and a Pittsburgh loss to the Lions to get the #6 seed.
If that happened, the Chiefs and Steelers would have 10-6 record, but the Chiefs would win the tiebreaker with a 9-3 conference record (versus Pitt's 7-5).
Here's the current seeding:
1 - Colts - 13-2 - clinched AFC South and homefield advantage throughout - can't lose #1 seed
2 - Broncos - 12-3 - clinhced AFC West - can't lose #2 seed
3 - Bengals - 11-4 - clinched AFC North - can lose #3 seed with NE win over NYJ and MIA, as well as a CIN loss in KC
4 - Patriots - 9-5 - clinched AFC East - can win #3 seed with NE win over NYJ and MIA, as well as CIN loss in KC
5 - Jaguars - 11-4 - clinched #5 seed
6 - Steelers - 10-5 - can lose #6 seed with KC win over CIN and PIT loss to DET
Non-eliminated teams still in the running:
7 - Chiefs - 9-6 - can win #6 seed with KC win over CIN and PIT loss to DET
WILD-CARD WEEKEND
Saturday, January 7: No. 5 Jaguars at No. 4 Patriots
Sunday, January 8: No. 6 Steelers at No. 3 Bengals
*The Patriots would host either the #6 Steelers or #6 Chiefs on Sunday, January 8th if they win the #3 seed*
DIVISIONAL ROUND
Saturday, January 14: TBD at No. 2 Broncos
Sunday, January 15: TBD at No. 1 Colts
*The #1 Colts play the lower-seeded winner of the Wild Card Round*
CHAMPIONSHIP GAME
Sunday, Jan. 22: TBD
*Higher-seeded winner from Divisional Round hosts*
SUPER BOWL XL
Sunday, Feb. 5: Ford Field, Detroit, MI