"Running back DeAngelo Williams was held out of Wednesday's because of a sprained foot, raising some doubt as to his availability for Sunday's game against the St. Louis Rams.

Williams injured his foot on the final minutes of Carolina's 23-20 win over the San Francisco 49ers on Sunday, but it's not believed to be serious.

Even if Williams doesn't play Sunday, the Panthers should be fine as running back is their deepest position. Jonathan Stewart would start, while Mike Goodson and Tyrell Sutton would work in off the bench.

Stewart is off to a rough start this season.

Through six games Stewart has just 148 yards and one rushing touchdown and is averaging a mere 4 yards per carry. That's a dramatic drop from last season when Stewart led the team with 1,133 yards rushing and 10 touchdowns while averaging 5.1 yards per carry.

In his final three games last year, Stewart ran for 109, 206 and 125 yards.

This year, he's not rushed for more than 43 yards in a game.

When asked for the reason in the drop in production, Stewart said "I don't know, many things," but wouldn't elaborate.

Stewart said injuries aren't a problem.

He hasn't missed a practice since the regular season began after missing numerous practices the previous two seasons and said he feels healthier this year than he did in 2009.

Of course, Stewart and DeAngelo Williams have had added pressure facing eight- and nine-man fronts throughout the season. The Panthers also have a new fullback in Tony Fiammetta, who replaced Brad Hoover.

"Instead of building up frustrations I have to believe in the guys in front of us that things will eventually starting opening up," Stewart said. "And that's not just the guys up front but the entire offense doing their job. It's a collective deal."

Stewart said he's optimistic that last Sunday's win over San Francisco will force teams to honor Carolina's passing game, thus preventing teams from putting extra men in the box."