Top three story lines

Must-win situation. After losing 30-17 at Indianapolis, the Texans have to defeat the Chargers to be 5-3 at the break because the more difficult part of the schedule is over the second half.

Winning is paramount. The Chargers are 3-5, and they still plan to win the AFC West. They can't afford to lose this game. At some point, they must win on the road, and this would be the time for them to do it.

Finding an identity. The Texans can't decide what they are: a running team or a passing team. The coaches want balance. Arian Foster has 737 yards rushing, a 5.7 average per carry and seven touchdowns. Matt Schaub has 10 touchdowns and six interceptions, but he hasn't played as well as last season.

Three key Texans

LT Duane Brown. Brown was beaten for two sacks by Colts defensive end Dwight Freeney. Brown played for the first time since returning from his four-game suspension. He's still going to be rusty, but if he doesn't improve, he could get embarrassed again, causing big problems for quarterback Matt Schaub.

DE Mario Williams. Williams had five sacks and 11 hurries in his first three games. He has no sacks and one hurry in the last three games, and the Texans have lost two of those games. Unless he can apply some consistent pressure on Philip Rivers, the secondary could get picked apart.

WR Andre Johnson. Johnson aggravated the high ankle sprain he suffered in the third game. He's played with it, but it caused him to miss one game. He had seven catches for 106 yards and a touchdown against the Colts. He limped off the field on the last Texans drive and didn't return. He should play against the Chargers.

Three key Chargers

QB Philip Rivers. Rivers has thrown for 2,649 yards, more than any quarterback in history after eight games. He's on a pace to throw for 5,298 yards, which would shatter Dan Marino's record of 5,084. The Texans have the worst defense, including the worst pass defense, in the NFL.

TE Antonio Gates. Gates has 40 catches for 663 yards and nine touchdowns. Heâ€™s on a pace for 1,326 yards and 18 touchdowns, which would break the records of 1,290 yards by Kellen Winslow Sr., and 13 touchdowns by Dallas Clark and Vernon Davis.

K Kris Brown. Brown is going to be under pressure when he lines up for field goals in the stadium where he played the last eight seasons. Brown, who has been the kicker for the last two games, was waived by the Texans in preseason. He was the last original Texan from 2002, but he was beaten out by Neil Rackers.

Bottom line: The Texans and Chargers are desperate for a victory. The Chargers are 0-4 on the road. The Texans are 2-2 at Reliant Stadium. The Chargers have the NFL's top-ranked defense, and the Texans have the worst defense. The Chargers play solid run defense and should be able to contain Arian Foster. This could be a shootout between quarterbacks Matt Schaub and Philip Rivers. If it is, the Texans better hope Schaub plays a lot better than he played at Indianapolis. Special teams have contributed to four of the Chargers' five losses. Thereâ€™s nothing special about the Texans' special teams, so don't expect them to capitalize on the Chargers' primary weakness.

Prediction: Texans 33, Chargers 30

--SN Correspondent John McClain