Mathieu and Moore are first-round talents who plummeted to the third round due to off-the-field concerns and war-room analysis paralysis. But since those two already have been highlighted by Around The League, let's take a look at 10 more rookies who could surprise in Year 1, despite falling out of the top 40 selections of the 2013 NFL Draft.
1. David Bakhtiari, Green Bay Packers offensive tackle
As we discussed on the Around The League Podcast, the fourth-round pick is the favorite to take over at left tackle following Bryan Bulaga's season-ending ACL injury. Bakhtiari started the preseason opener and didn't allow a quarterback pressure in his 19 pass blocks. It was an encouraging showing, but he will have to show improvement as a run blocker.
2. Kenbrell Thompkins, New England Patriots wide receiver
Regular NFL.com readers already are familiar with the undrafted free agent-turned-training camp darling. NFL Network analysts Daniel Jeremiah and Mike Mayock have turned in glowing reports after viewing Patriots practices, and Gregg Rosenthal has consistently sung Thompkins' praises on the Around The League Podcast. The question entering camp was whether Thompkins would emerge as the team's top offensive rookie. Three weeks later, many are wondering if he can challenge Danny Amendola as the best all-around receiver.
3. Robert Alford, Atlanta Falcons cornerback
It's only one preseason game, but I noticed that ProFootballFocus.com assigned a lower grade to Desmond Trufant than any other first-round pick while Alford earned one of the highest grades for second-round picks. Although both rookies have impressedonlookers, Alford has generated more buzz for his aggressiveness and physicality.
4. Sio Moore, Oakland Raiders linebacker
A Mayock favorite, Moore is a complete linebacker capable of stopping the run, hanging with tight ends in coverage and closing quickly on quarterbacks as a pass rusher. After handing Moore the starting strongside job, Raiders coach Dennis Allen said he envisions the third-rounder being used in a similar fashion as Von Miller with the Denver Broncos.
5. Markus Wheaton, Pittsburgh Steelers wide receiver
Wheaton already looks like not just a third-round steal but also an NFL-ready replacement for Mike Wallace. A precise route runner with plus speed, good size, reliable hands, toughness and a high football IQ, Wheaton flashed plenty of playmaking ability in the preseason opener. Expect him to open the season as the No. 3 receiver with a chance to expand that role by November or December. Jeremiah is confident that Wheaton will be embraced immediately in the Steel City.
6. Jon Bostic, Chicago Bears linebacker
7. T.J. McDonald, St. Louis Rams safety
The Rams have shown no interest in bringing back veteran Quintin Mikell primarily because McDonald has been such a quick study as the starting strong safety. Coach Jeff Fisher revealed Tuesday that McDonald's development has advanced to the point where the third-rounder already is making defensive calls. Fisher is plenty familiar with McDonald, having coached his father, Tim, with the San Francisco 49ers.
8. Kawann Short, Carolina Panthers defensive tackle
The Panthers internally view Short as a more explosive pass rusher than No. 14 overall pick Star Lotulelei. The early results have been encouraging for the second-rounder, who tallied two hurries and one quarterback hit on 18 rushes in the preseason opener. The Panthers' defensive front seven has the potential to be among the NFL's best this season.
9. Ace Sanders, Jacksonville Jaguars wide receiver
The Rams' fallback option to Tavon Austin, Sanders has a similar game with much less hype. The Jaguars knew they were getting a slot receiver and explosive kick returner, but they soon discovered Sanders was a complete receiver who also could win matchups on the outside. Described as a "revelation" and a "straight beast" in camp, the fourth-rounder has emerged as the favorite to start opposite Cecil Shorts while Justin Blackmon serves a four-game suspension.
10. Stepfan Taylor, Arizona Cardinals running back
The fifth-rounder out of Stanford arrived in the desert as an NFL-ready pass protector and route runner, two qualities often lacking in rookie tailbacks. With a snakebitten Ryan Williamsfacing the roster guillotine, Taylor could enter the season behind only Rashard Mendenhall on the depth chart. Considering Mendenhall's durability issues, Taylor might be thrust into the featured back role before the end of the season.