Zac Stacy sits out Wednesday practice with Rams

Running back Zac Stacy did not practice with the St. Louis Rams on Wednesday. He was held out with what's listed as a chest injury. Head coach Jeff Fisher was not overly concerned about Stacy's status for a Week 6 game in Houston.

"He took the day off," Fisher said after practice on Wednesday. "He's a little sore after that outing, but he'll be fine."

Stacy got his first start of the season, his first meaningful action in the NFL, against the Jaguars last week. The rookie from Vanderbilt carried the ball 14 times for 78 yards. His average of 5.6 yards per carry is unmatched by any other running back on the Rams roster this season.

That performance marked the first time this season that the Rams have attempted to run the ball more than a total of 30 times in one game. Fisher promised more balance ahead of last week's game, and the offense delivered. Emphasizing the run also helped quarterback Sam Bradford, who threw a pair of touchdown passes on play action.

"We knew going into last week that after the previous two weeks where we had become very one dimensional," Bradford said Wednesday. "It was going to be important for us to establish the run game and stay balanced throughout the game. All the running backs who came in ran extremely hard, and I think that balance really helped maintain throughout four quarters."

Richardson carried his share of the workload last week too. He ran the ball 13 times for 48 yards in relief of Stacy.

Houston's run defense has underwhelmed this season. The Texans are allowing an average of 126 yards per game and 4.2 yards per attempt. Compare that to last season when Houston's opponents averaged 97.5 rushing yards and four yards per carry.

"We've got to run the football to score points," Fisher said of this week's game plan.

More injuries

Cortland Finnegan and Rodger Saffold joined Stacy on the sidelines during Wednesday's practice. Saffold is still recovering from a knee injury. Finnegan is dealing with a hamstring injury.

William Hayes returned to practice this week, albeit on a limited basis. Matt Conrath was also limited in practice.

Houston's injury report had a new name on it this week: Andre Johnson. The veteran wide receiver was out with a hamstring issue on Wednesday, a new development. However, he has yet to miss a game this season, despite frequent battles with minor aches and pains.

Here's the rest of the Texans injury report:

Did not participate: LB Tim Dobbins (hamstring), WR Andre Johnson (shin), WR Keshawn Martin (shoulder), LB Darryl Sharpton (foot), G Wade Smith (knee).

Limited: LB Bryan Braman (neck, knee), G Brandon Brooks (toe), T Duane Brown (toe), RB Arian Foster (thumb, chest), S Ed Reed (knee).