From future Hall of Famer Marshall Faulk to second-round draftee Brian Leonard to journeymen such as Arlen Harris, Tony Fisher and Antonio Pittman, the Rams for half a decade have strived to find a solid backup for Pro Bowl running back Steven Jackson.

In general, it's been a futile search. Leonard produced 303 rushing yards in 2007, the highest total among the No. 2 backs. Pittman had 296 in '08 and Faulk 292 in '05. None of the others cracked the 200-yard mark.

Meanwhile, Jackson has rolled up a total of 6,034 yards (on 1,414 carries) in his five seasons as the team's marquee back, topping 1,000 yards in each of those seasons. During that period, Jackson has averaged 282.8 carries a year, one of the NFL's heaviest workloads.

His carries and yards represent 75.6 percent and 77.2 percent, respectively, of the Rams' ground production by running backs in that span.

Now, Jackson is coming off surgery April 15 to repair a herniated disk in his lower back. So, it would seem logical that the Rams would prefer to lessen Jackson's task a bit.

The Rams have flirted with former Philadelphia standout Brian Westbrook, a free agent brought in for a physical exam last month. The Rams remain interested, but Westbrook, 30, has a troublesome left knee and also suffered two concussions last season.

Two rookie free-agent running backs — Keith Toston of Oklahoma State and DeMaundray Woolridge of Idaho — are among the 96 players participating in organized team activities at Rams Park.

But with training camp about two months off, the only other backs on the roster with NFL experience are holdovers from last season, Kenneth Darby and Chris Ogbonnaya.

They've heard the pleas for a new face to back up Jackson, and it's possible the Rams will find one when rosters are whittled down in the summer.

Still, Darby and Ogbonnaya would like to say: Hey, what about us?

"They should all think that way," coach Steve Spagnuolo said. "Any back that comes in here should be competing for that" job.

"People are going to talk, and I really can't control what people say," said Darby, 5 feet 10 and 219 pounds. "But I can control what I do on the field. When people say that, I don't really pay it any mind. But I do remember it, so when I get my opportunity to go out there, I show people what I'm made of and introduce them to Mr. Kenneth Darby."

Last year, Mr. Darby picked up 152 yards on 27 carries and added 96 yards on 18 catches. Ogbonnaya, 6-0 and 225, spent most of his rookie season on the practice squad. But he suited up late in the year and had 50 yards on 11 attempts, plus one reception for 19 yards.

That action, scant as it was, "helps a lot," Ogbonnaya said. "When you're just out there practicing, you're more so working on your craft instead of working toward getting ready to play on Sundays. Getting that experience ... helped me to understand the speed of the game, how it's different on game day as opposed to practice."

Preparing for his second season is "a lot different," said Ogbonnaya, a former University of Texas ballcarrier. "I'm a lot more comfortable. I understand the system fully. Now, it's just working on the technical aspect of things."

To make a legitimate run for the No. 2 spot, Ogbonnaya said he needs to "just play consistently, play fast, and do the things that I know that I can do best. Just do me. That's the most important thing. Just go hard every play and put yourself in the position that ... gives the coaches a chance to evaluate where you're at in a positive light."

Darby is an Alabama product who said he enjoys the competition.

"That's what makes it so fun," he said. "It makes me a better player, and it makes the person I'm competing against — all the running backs — better."

He was the busiest stand-in for Jackson last year, and Darby said he regards his incumbency as a positive.

"Most definitely. I feel like I can secure that" job, he said. "I know all the players, I'm comfortable with the playbook, and I know what I'm doing when I'm out there.

"I feel like I'm very experienced in that area and that I can back up 'Jack' whenever they need me to go in there."

Ogbonnaya is equally self-assured.

"I feel confident; I would be lying if I didn't say that," he said. "But I know the nature of the business. It's my job to accept competition wherever it is. And I accept that challenge."