We devoted a segment of Wednesday's Around The League Podcast to a discussion of the NFL's most impressive and most disappointing rookies. Below is our list of the first-year players making the biggest impact through six weeks of the 2013 season.
1. Kiko Alonso, Buffalo Bills linebacker: The No. 46 overall pick in the 2013 NFL Draft leads the NFL in tackles (66) and interceptions (4). Although Alonso can thank a generous hometown scorer for the inflated tackles total, he's still been a difference-maker in Mike Pettine's defense.
2. Sheldon Richardson, New York Jets defensive end: Damon "Big Snacks" Harrison has been a mainstay in our "Making the Leap" series, but Richardson has been nearly as dominant against the run while adding a pass rushing element. The Jets' star-studded defensive line is holding opponents to a league-low 3.0 yards per carry.
3. Giovani Bernard, Cincinnati Bengals running back: Jay Gruden's offense finally has a second playmaker to complement A.J. Green. No rookie is within 100 yards of Bernard's 438 yards from scrimmage. His ankle-breaking 20-yard touchdown against the Bills looked like a clip from a Barry Sanders highlight video.
4. Eddie Lacy, Green Bay Packers running back: Lacy is the first Packers rookie since John Brockington in 1971 to rush for at least 99 yards in back-to-back games. With Randall Cobb out at least eight weeks and James Jones nursing a PCL sprain, Lacy could be the focal point of the offense in a rejuvenated ground attack.
5. Tyrann Mathieu, Arizona Cardinals defensive back: The steal of the NFL draft, Mathieu has been an every-down asset as a slot corner, outside cornerback and deep safety. We knew about his natural playmaking instincts, but his tackling ability and run support have been just as impressive, drawing comparisons to former Vikings Pro Bowler Antoine Winfield.
6. Star Lotulelei, Carolina Panthers defensive tackle: Every couple of games, Carolina's defense just slaps an offense around. Lotulelei has been instrumental in the improved run defense, shutting down the interior.
7. Eric Reid, San Francisco 49ers safety: It's not hyperbole to suggest that Reid is a playmaking upgrade on Dashon Goldson, a first-team All-Pro in 2012. The first-rounder's range jumps off the screen on Game Rewind.
8. Keenan Allen, San Diego Chargers wide receiver: We've pointed out Allen's emergence as Philip Rivers' go-to receiver in back-to-back prime time games the past two weeks. A first-round talent who slid to the third, Allen is a complete receiver playing with a veteran's savvy.
9. Kyle Long, Chicago Bears guard: Jay Cutler is off to the best start of his career in no small part because of the upgraded offensive line. Long already has the look of a perennial Pro Bowl selection.
10. Larry Warford, Detroit Lions guard: Marc Sessler has outlined Warford's role in Reggie Bush's success. The third-rounder has also exceeded expectations in pass protection, keeping Matthew Stafford clean in the pocket.
11. Kenny Vaccaro, New Orleans Saints safety: Defensive coordinator Rob Ryan is asking a lot of the No. 15 overall pick, lining him up as a deep safety, an in-the-box safety, a nickel back in the slot, a cornerback on the outside, an inside linebacker and an outside linebacker. Vaccaro has been one of most important players on a defense that has gone from overly generous to downright stingy.
12. Marcus Cooper, Kansas City Chiefs cornerback: If Mathieu was the steal of the draft, then Cooper is the steal of the waiver wire. Claimed from the 49ers after final cuts, the seventh-rounder has been sticky in coverage while turning in momentum-changing interceptions in back-to-back games.
13. Andre Ellington, Arizona Cardinals running back: The sixth-rounder has been a big-play machine, picking up a first down 19 times on 43 touches -- good for a 44 percent conversion rate. For comparison's sake, Adrian Peterson and LeSean McCoy move the chains less than 30 percent of the time.
14. Travis Frederick, Dallas Cowboys center: An offensive line that was expected to be a weakness has instead been one of the NFL's strongest thus far. Frederick's steadily improving play is a big reason for the turnaround up front.
15. Alec Ogletree, St. Louis Rams linebacker: Ogletree remains a work in progress, taking Magellan-like routes to the ball and missing too many tackles. His knack for big plays has been evident going back to the preseason, though.