With injuries really beginning to pile up around the league, more rookies stepped into starting lineups around the NFL in Week 6. Most of these first-year players use their increased opportunities to impress, while others struggled to make an immediate impact.

Delone Carter (RB-Ind)

Starting in place of the injured Joseph Addai, a Week 5 development that surprised nobody, Carter was one of those rookies who struggled to take advantage of his increased playing time. The Colts’ fourth-round pick out of Syracuse, Carter had 14 carries for 45 yards against the Bengals on Sunday and was outplayed by third-year bust Donald Brown, who had 35 yards and a touchdown on just 5 carries.

Carter came out of the preseason with a lot of hype, but early returns so far in 2011 say he’s no more than the situational runner we at Draft Insider projected him to be before April’s draft. He has yet to show the power many would expect from a 5-8, 220-pound runner and isn’t showing the vision or instincts that had the Colts so high on him. Carter is averaging barely over 3 yards per carry and has just 2 receptions for 12 yards on the season.

While Addai might miss Indianapolis’ upcoming game against the Saints too, it may be Brown who sees more work since he was more effective as a runner and more active in the passing game last week and considering the Colts are likely to be playing from behind against a motivated New Orleans team coming off a loss to Tampa Bay. Addai’s injury history means Carter will likely receive another shot at some point this season, but he will need to do more with it when he does to stave off a seemingly rejuvenated Brown.

Greg Little (WR-Cle)

Replacing Brian Robiskie in the starting lineup out of Cleveland’s Week 5 bye, Little already looks like Colt McCoy’s new favorite target. McCoy threw 45 passes with the Browns trailing most of the day, but 12 of them were intended for the former North Carolina standout, who caught 6 of them for 72 yards just a week after making 6 receptions for 57 yards.

The Browns grabbed Little late in the second round of the draft, but he is a player with first-round upside. He didn’t play in 2010 due to NCAA rules violations, which contributed to his fall outside the top 50 picks. Little isn’t a burner but at 6-2, 220 pounds he’s a big target with good hands and, as a former running back, has the ability to make big plays with the ball in his hands after the catch.

Expect Little to continue his ascent to the top of the Cleveland depth chart at wide receiver and actually find the endzone for the first time in the coming weeks. He would have had an easy touchdown on Sunday, but slipped at the one-yard line after catching a short pass inside the five. With his playmaking ability, it shouldn’t be long until he gets close again.

Greg Salas (WR-StL)

A fourth-round pick from Hawaii, Salas got an opportunity to play in Week 2 thanks to a struggling group of Rams receivers. After a drop-plagued performance where he also lost a fumble, Salas was back on the bench in Weeks 3 and 4. But exiting their bye week, St. Louis put Salas back in the slot against Green Bay.

The 6-1, 209-pound receiver thrived in that role in Week 6, catching 8 of the 10 passes thrown his way for 77 yards and, most importantly, dropping just one pass and showing good quickness in picking up yards after the catch. Even with the Rams’ acquisition of Brandon Lloyd and the impending return of Mark Clayton from the PUP list, Salas may be able to stick in the slot at least until Clayton gets up to speed.

His reliable hands, ability to find holes in zone coverage and run-after-catch ability give Salas the potential to be one of the more effective underneath receivers in the NFL. The Rams should recognize this and continue to give him the opportunity to succeed, as long as he can keep the drops to a minimum. On a team going absolutely nowhere this season, there’s no reason to send Salas to the bench for a veteran like Clayton if he can remain productive.

Lance Kendricks (TE-StL)

Like Carter, Kendricks was another mid-round rookie who was expected to make a big impact from the outset. After an impressive preseason where he showed excellent chemistry with Sam Bradford, the second-rounder out of Wisconsin was expected to be one of Bradford’s top targets considering St. Louis’ lack of receivers.

Instead, Kendricks disappointed greatly through the Rams’ first four games. Plagued by drops, the former Badger caught just 8 of the 21 passes thrown his way and quickly, expectations were tempered. But Kendricks showed signs of life against Green Bay on Sunday, making 4 receptions for 71 yards on 6 targets. He still hasn’t cured his hands, however, dropping a fourth-down pass in the fourth quarter with the game already decided.

Kendricks is a big target and a natural pass-catcher who has struggled to show off his strong hands early in his NFL career. Draft Insider said he was likely to be overdrafted due to a weak tight end class and so far, the top-50 pick St. Louis spent on him looks to be a reach. Kendricks still has time to turn things around, as he’s not the only Rams offensive player who has struggled, but as a one-speed player who struggles to create mismatches downfield and get movement blocking, he may not be able to find a useful niche in the league if he’s not catching everything thrown his way.

Tyron Smith (T-Dal)

Most rookie offensive lineman, even first-round picks, tend to struggle in their first year. Smith, the 9th pick in April’s draft, bucked that trend early this year and graded out as one of the league’s top tackles through Dallas’ first three games.

Smith has come back to earth a bit in the Cowboys’ last two games, however. The former USC tackle allowed a huge sack late in their Week 5 game against Detroit that essentially ended any chance of a last-minute comeback, despite receiving great reviews for his performance in the first 59 minutes. He also got beat by veteran Andre Carter while Dallas was driving inside New England’s 10-yard line on Sunday, forcing Dallas to settle for a field goal to tie to game at 13.

Overall, Smith has been solid through five games and has received high praise from the Cowboys staff, even being compared to a young Larry Allen by offensive line coach Hudson Houck. Starting at right tackle while Doug Free struggles at left tackle, Smith has the potential to eventually move over to protect Tony Romo’s blind side in 2012.

His talent was never in question with the size (6-5, 307), athleticism and the upside to justify being a top-10 selection, but his work ethic has also been lauded so far. If Smith continues to develop at a rapid rate, he could become one of the league’s best tackles within a season or two.

Stephen Paea (DT-Chi)

With the Bears needing extra help along their defensive line, the team’s second-rounder out of Oregon St. was active for the first time this season. Despite his inactivity, the Bears remained high on Paea’s potential and it didn’t take him very long to make a noticeable impact Sunday night against Minnesota.

On his second career play, Paea sacked Donovan McNabb for a safety. On his third career play a drive later, he tripped up Adrian Peterson in the backfield. His impact plays early in the game led to him seeing a lot more of the field on Sunday than anybody expected.

While Paea is just 6-1, 303 pounds, he fits well as a three-technique tackle in Chicago’s 4-3 defense. He is explosive off the snap, plays with a great motor and shows good moves to get off blocks. Paea drew constant double-teams with the Beavers and while he’s unlikely to garner the same attention on the NFL level, he definitely has the upside to start as a one-gap tackle. Look for him to stay active for the rest of the season and see increased work in the Bears’ defensive line rotation.

Brooks Reed (LB-Hou)

The Texans’ second-round pick out of Arizona, Reed has stepped into the starting lineup to replace All-Pro Mario Williams, who was lost for the season to a pectoral injury. Despite not registering a sack in his first career start, Reed impressed with 6 tackles (3 solo) and a pass breakup.

At 6-2, 260 pounds with a non-stop motor, Reed has the ability to be an impact player right away. He won’t match Williams’ production, but few players in the NFL can. At the very least, his speed and quickness off the edge will provide the Texans with a pass-rushing presence that should at least force opposing teams to acknowledge his presence.

Reed won his share of battles at the line of scrimmage against Oakland and Baltimore in the running game, giving Houston hope that he can be a productive three-down player for the rest of the season. The experience he’ll gain as a starter should aid his development down the line and a good 10-game audition the rest of the way could prepare him for a similar role in 2012.

Demarcus Van Dyke (CB-Oak)

The raw Van Dyke started his second straight game in place of Chimdi Chekwa and held his own in the Oakland secondary, making 2 tackles and breaking up 2 passes after registering 4 tackles in Week 5. Before stepping in to replace Chekwa, Van Dyke was best-known for running one of the fastest 40-yard dash at the combine.

Van Dyke’s sub-4.30 speed made him a logical choice to be drafted by the late Al Davis’ organization in the third round of April’s draft. The Miami product struggled to put it all together on the collegiate level but has the talent play his way into an eventual starting role at the NFL level, and not just when injuries hit.

In addition to his blazing speed, Van Dyke is physical with receivers and aggressive in the running game despite his slim build (6-0, 176). Ideally he would be nothing more than a nickel back at this stage of his career, but injuries in Oakland’s secondary have forced him into the starting role. Van Dyke is still a project but offers potential as a speedy cover corner that can also play the run. Complete corners like that are hard to find in the NFL, but it remains to be seen how Van Dyke will develop.

Chris Tripodi has been writing for Draft Insider since 2009, compiling Rookie Reports and Draft Reviews and interviewing NFL prospects. He has been a sportswriter for multiple newspapers and has previously worked at ESPN and with the Rochester Red Wings, the Minnesota Twins’ Triple-A affiliate. Follow him on Twitter (@christripodi) and check out his blog at http://christripodisports.blogspot.com.