No assembly required. Batteries included. Rookie running backs don't come into the NFL wearing such labels, but they are showing again this season that they arrive ready.

Matt Forte of the Chicago Bears, Darren McFadden of the Oakland Raiders, Chris Johnson of the Tennessee Titans and Steve Slaton of the Houston Texans lead their teams in rushing. Jonathan Stewart is smashing for touchdowns with the Carolina Panthers. Felix Jones is making big plays with the Dallas Cowboys.

Like all rookies, they face adjustments. For running backs, that includes blocking on pass protection. But running skills translate immediately.

Last February at the NFL scouting combine, all six showed they could run the 40-yard dash very fast in shorts. Now, they're running in full pads with footballs in their hands.

"For the most part, they're not doing anything differently than they've been doing their whole lives. It's all about making people miss," says Mike Mayock, draft analyst for the NFL Network. "At each level it gets harder because the athletes get better. But I think it's the position in the NFL where a rookie can step in."

This year, that theory is proving to be true. According to the Elias Sports Bureau, rookie running backs have 550 rushing attempts for 2,407 yards. Both totals are the most through the first five weeks since 2001 (628 attempts, 2452 yards).

With the NFL's current strategy leaning toward teams using two running backs to share the load, the rookies are getting their shots. USA TODAY looks at the top six running backs in this year's freshman class:

• MATT FORTE, BEARS

Chicago drafted the 6-2, 216-pounder from Tulane in the second round after five running backs had gone in the first. Forte figured to compete with incumbent Cedric Benson for the starting job. But the Bears cut Benson in June after his second alcohol-related arrest in a month.

In an opening day start against the Indianapolis Colts, Forte ran 50 yards for a touchdown in the first quarter and totaled 123 rushing yards. He's been the starter since and tops all rookies in rushing yards (383) and carries (107). He's run for two touchdowns and caught 22 passes for 172 yards and two touchdowns.

Forte has dropped to an average of less than three yards per carry in his past two starts. But last week against the Detroit Lions he scored two TDs on a 9-yard reception and a 1-yard run.

"The thing you like about this guy is he's very versatile," says Philadelphia Eagles defensive coordinator Jim Johnson. "He can block, he stays in on nickel defense, he's got good hands, he catches the ball, and he's one of the top receivers that they have right now.

• CHRIS JOHNSON, TITANS

He's started four of five games and tops the Titans with 381 rushing yards, while sharing carries with 235-pound LenDale White.

"I watched a lot of tape of him (Johnson) at East Carolina, and I didn't think he liked to run between the tackles," says Mayock of the 5-11, 200-pounder. " … But they have really used him well and he's run hard."

The 24th pick in the first round, who ran the fastest time of any player at the NFL's scouting combine (4.24), is no surprise to coach Jeff Fisher.

"You don't draft someone in the first round with question marks. We had high expectations for him," Fisher says.

• FELIX JONES, COWBOYS

At Arkansas, he was a playmaker as a backup to Darren McFadden and a kick returner. Dallas made him the No. 22 overall pick.

ROOKIE FOCUS: Felix Jones sees Hall of Fame in his future

Marion Barber anchors the running game. But while the 5-10, 207-pound Jones has rushed just 27 times, he has averaged nine yards per carry and scored three rushing touchdowns. Last week he had a 33-yard TD run vs. the Cincinnati Bengals. He also returned a kickoff 98 yards for a score against the Philadelphia Eagles in Week 2.

"Felix Jones might not get as many carries as the rest of these guys, yet he might have the biggest impact down the road because the touches he gets with the Cowboys are quality touches with a good team," Mayock says.

• DARREN McFADDEN, RAIDERS

His time of 4.33 seconds in the 49-yard dash at the NFL combine ranked second among running backs and solidified the 6-2, 200-pounder from Arkansas as the top-rated running back. He came in with potential along the lines of 2007 rookie rushing star Adrian Peterson of the Minnesota Vikings.

In the Raiders' second game, against the Kansas City Chiefs, McFadden ran 21 times for 164 yards and a touchdown. But he suffered a big toe injury (turf toe) in that game. In two starts since, he's totaled 21 carries for 62 yards.

McFadden has shared carries with 245-pound Michael Bush and Justin Fargas. With Fargas expected back this week after missing two weeks with a groin injury, he, McFadden and Bush all figure to play Sunday at the New Orleans Saints. "It's a good mix with (Fargas) and Darren and Michael," says new Raiders coach Tom Cable.

• STEVE SLATON, TEXANS

When he was drafted, the 5-9, 201-pounder from West Virginia looked like a potential third-down back. But with Ahman Green sidelined by a knee injury, Slaton got the start in the Texans' second game, against Tennessee, and he ran for 116 yards and a touchdown. He's started the past three games and leads Houston with 285 rushing yards.

"He's been one of the big surprises of the year," Mayock says. "A lot of people had him going fourth, fifth, sixth round because there was a perception he was too small and too fragile playing in that spread offense at West Virginia."

Slaton set out to show he's more than a third-down back. "I think that's any running back's mentality," he says. "You don't want to be labeled as just one position or one down. You want to carry the ball as many times as you can."

• JONATHAN STEWART, PANTHERS

The 5-10, 235-pounder from Oregon has not started for Carolina, but he has been a factor in the running game along with third-year pro DeAngelo Williams.

He leads the Panthers with four rushing TDs. Last week against the Kansas City Chiefs, while Williams was running for 123 yards and two touchdowns, Stewart ran a career-high 19 times for 72 yards.

Stewart, the second running back taken in the draft and the No. 13 pick overall, says he and Williams aim to wear down defenses.

"Wear and tear, no matter who is in the backfield," Stewart says. "Just keep pounding."