Chris Tripodi is back to break down the performances of more NFL rookies through the first quarter of the season after taking an extended look at some early-round draft picks and getting his first look at a few others.

Ryan Mathews (RB-SD)

The second running back off the board in April’s draft, Mathews has been slowed early in his rookie season by an ankle injury he suffered in Week 2 against the Jaguars. He was eased back into action this week with 9 carries for 55 yards and a touchdown, most of them coming in the second half when the Chargers had the game in hand.

After a solid week 1 where he ran for 78 yards on 20 carries, Mathews was hurt after just 5 carries against Jacksonville and missed San Diego’s Week 3 matchup with the Seahawks. After this week’s win against Arizona, Norv Turner committed to Mathews as his featured back as he works his way back to full strength despite the effectiveness of backup Mike Tolbert, as his injury has stunted Mathews’ development early in his rookie season.

Mathews’ isn’t a burner or a bruiser but has the speed, power and receiving ability to be a suitable replacement for LaDainian Tomlinson, who has thrived so far this season with the Jets after being let go by San Diego in the offseason. Look for Mathews’ workload to increase in the coming weeks as long as he stays healthy and outperforms Tolbert.

David Nelson (WR-Buf)

An undrafted rookie out of Florida, Nelson opened some eyes this week against the Jets with 4 catches for 75 yards, including a 37-yarder. Sitting fourth on the depth chart in Buffalo, he had gone without a catch in his previous two games after catching three balls in the opener.

Nelson was a longshot to make the team out of camp but has the size (6-5, 214) and hands to be a productive possession receiver at the NFL level. He does the little things well, running crisp routes and helping running backs get extra yardage with his terrific blocking ability down the field. However, Nelson lacks the speed to stretch the field and won’t be more than a fourth or fifth receiver in the future unless he plays to his size and develops into a more reliable red-zone option.

Jermaine Gresham (TE-Cin)

Four games into his rookie campaign, Gresham is already developing into one of Carson Palmer’s favorite targets in the short passing game. The first-round pick from Oklahoma is third on the team with 18 receptions and 134 yards after missing his senior season with a knee injury.

Gresham is a raw talent who was a very effective downfield receiver with the Sooners. His blocking leaves a lot to be desired and he has a tendency to lose focus, but has the potential to wreak havoc on linebackers and safeties once gets back to full strength and figures out the nuances of the NFL game.

Once he starts creating more separation downfield and catching the eye of Palmer, he should be able to stretch defenses and put up better yardage numbers than he has early on. But with Chad Ochocinco and Terrell Owens dominating the downfield looks, that may be easier said than done this season for Gresham.

Gerald McCoy (DT-TB)

Another Oklahoma product, McCoy was one of two defensive tackles drafted in the top three. While second overall pick Ndamukong Suh has put up gaudy numbers through four games including 15 tackles and 3 sacks, McCoy has just 5 tackles and no sacks in three games for Tampa Bay.

But his stats don’t measure the impact he has had on the Tampa defensive line. McCoy is already a focus of opponents’ gameplans, drawing consistent double-teams since the season’s first week and even facing a few triple teams in Week 2 against Carolina.

McCoy may never be the game-changing presence that Suh already is, but he has the potential to be one of the better interior linemen in the league as he continues to develop. He won’t put up big tackle or sack numbers, but defensive tackle is one position where stats rarely tell the whole story and McCoy will continue to draw lots of attention from offensive coordinators around the league.

Joe Haden (CB-Cle)

The Browns’ first-round pick out of Florida, Haden is doing his best to break into the Cleveland starting lineup. Eric Wright remains the starter opposite Sheldon Brown but Wright had his share of troubles covering Anquan Boldin in Week 3.

Haden had 6 tackles and a pass defensed against the Bengals on Sunday but ended up on the ground trying to cover Owens on a deep out late in the second quarter. Haden was slow out of his plant, dove to break up the pass and missed, allowing Owens to run free for extra yardage. That wasn’t the only play he was beat on, either.

While Haden has had a few growing pains he represents the future for the Browns at corner, but with the team sitting at 2-2 he won’t break into the starting lineup until the coaching staff feels he’s ready. With everybody else in the Cleveland secondary getting burnt as well, Haden’s opportunity to start may still come soon despite his own uneven play.

Alterraun Verner (CB-Ten)

Replacing the injured Jason McCourty on Sunday, Verner played well in his first career start with 11 tackles and 3 passes defensed.

We had Verner rated as a second-round prospect coming out of UCLA, but he fell to the Titans in round four. What he lacks in top-end speed and size he makes up for with good awareness, instincts and physicality in both the running game and the passing game. While Verner had lots of chances to make plays against the Broncos, he also got beat for an early touchdown. Lined up on Eddie Royal in the slot, he couldn’t get outside quick enough to break up the pass as he was picked coming across the field.

McCourty’s injured forearm will likely require surgery, meaning Verner will start opposite Cortland Finnegan for the foreseeable future. If he can build on his performance Sunday, he may keep the job for the rest of the season and beyond.

Perrish Cox (CB-Den)

Cox got his second straight start in place of the injured Andre Goodman on Sunday and struggled at points, like he did against the Colts in his first start. Cox looked overwhelmed covering Austin Collie and was picked apart by Peyton Manning, allowing a touchdown to undrafted rookie Blair White. He had three tackles and four passes defensed in the game, but much of that was a result of Manning constantly looking to exploit Cox’s inexperience.

Cox also muffed a punt in Week 3 and was replaced in that role by Eddie Royal. Demaryius Thomas took over for Cox as the team’s primary kick returner as well and to say it hasn’t been a good two weeks for Cox would be an understatement. He didn’t fare much better this week against the Titans, getting beat by Kenny Britt for a touchdown on a crossing route.

If Goodman is able to return in Week 5, Cox will be sent back to the bench and see time only in nickel and dime packages. It’s pretty obvious he needs more polish before developing into a starter, but the potential is there for him to be an effective second corner down the line.

Taylor Mays (S-SF)

Mays got the start in Week 4 over Michael Lewis and played like he wanted to keep the job, leading the team with 11 tackles and scoring a touchdown on special teams. Lewis had just 10 tackles in the team’s first three games and was released on Monday.

Mays’ touchdown came when he caught a blocked punt in the Falcons end zone, displaying impressive footwork to tap his toes inbounds and hang onto possession. Not known for his hands or ball skills, this was a big play for Mays in his first career start. He was heavily involved in run support, something that should be expected out of him on a week-to-week basis.

Many thought Mays was a first-round talent but he fell into the second round in April’s draft due to questions about his ability in coverage. Mays is great playing near the line of scrimmage and has good straight-line speed, but plays stiff and struggles getting out to the flanks and playing center field in pass defense. It remains to be seen whether he can cover well enough to round out his game and become one of the league’s better all-around safeties, but Mays is a big hitter who will always have an impact in the running game.