(Eds: With AP Photos.)

By R.B. FALLSTROM

AP Sports Writer

ST. LOUIS (AP) - Without doing much in the second week of the preseason, Daryl Richardson solidified his status as the St. Louis Rams' front-runner at running back.

``I mean basically from a starting standpoint, yeah, I think Daryl will probably take the first snap against Arizona,'' coach Jeff Fisher said after practice Monday night.

``But as far as who's going to come in, that remains to be seen. We still have some more evaluating to do.''

That puts Isaiah Pead on notice.

Fifth-rounder Zac Stacy, who did not play Saturday against Green Bay, and undrafted Benny Cunningham also are in the mix.

Pead got the start against the Packers, giving coaches a better chance to evaluate him with the first-string players.

But he didn't help his chances by gaining just 19 yards on 11 carries in a 19-7 loss.

The soft-spoken Richardson got called into the head coach's office the day before the game, but just to be told he wouldn't get many snaps and not to worry about it. He said Fisher still hasn't told him ``flat out'' that he's the starter.

I thought I was in trouble,'' Richardson said with a laugh.When you do go up there, if it's something good, then it's good.''

Richardson played sparingly, but his 24-yard reception was among Sam Bradford's top plays.

Richardson was a surprise success story last season, getting taken with the next-to-last pick of the NFL draft off a small college resume.

He's fifth on the career rushing list at Abilene Christian, which is moving up from NCAA Division II to FBS this season.

His 5.9-yard average as a senior hinted at other attributes. He's been quick, decisive and durable in the NFL, gaining 475 yards with a 4.8-yard average as Steven Jackson's backup last year.

I'm just glad they took the opportunity to have me come up here and show what I can do. You've got to have confidence to believe in yourself,'' Richardson said.If you believe, you can achieve anything.''

During his elongated wait to be drafted, Richardson said he never doubted he'd have a chance and recalled a ``joyful and happy'' experience.

It was a long wait but everything worked out,'' he said.As long as I got drafted, really as long as I got a shot, free agency or the draft ...''

Pead opened with an 11-yard carry from the Rams' 19 that Fisher said might have gone the distance if a wide receiver made a block.

Pead was happy with the pass-blocking and unhappy with the minuscule production and ``small mistakes that are Day 1 things, things I can rep 100 times and get corrected.''

Pead was the MVP of the 2012 Senior Bowl and the 2011 Big East offensive player of the year at Cincinnati and led the conference with 1,259 yards and 12 TDs.

But he fell behind other rookies while waiting for his class to graduate, and appears to still be playing catch-up.

In the preseason opener, Pead lost a fumble that led to a touchdown. When he gets a chance in Week 3, he realizes he must take advantage of it.

You have to stick to your rules,'' Pead said.You sit in the classroom and you're being coached and then you go out and do something different, that's not acceptable.''

Safety Darian Stewart missed practice while getting tests for a hamstring injury that he mentioned after the game.

Wide receiver Tavon Austin was an excused absence.

The players ran several sprints after the practice as a reminder of the mistakes made against the Packers.

The Rams (0-2) play at Denver (1-1) on Saturday with most starters getting extended playing time.

AP NFL website: http://pro32.ap.org