The two best teams in the NFC last year, the Atlanta Falcons and Dallas Cowboys, had one very important thing in common: They earned significant contributions from their rookies.

The Falcons started four rookies in their back seven in Super Bowl LI, including both of their top linebackers, and the Cowboys rode the legs of Ezekiel Elliott and the arm of Dak Prescott to the best record in the NFC in the regular season.

Rookies weren't the only reason the Falcons and Cowboys found themselves contending after disappointing 2015 seasons (when Dallas went 4-12 and Atlanta was a middling .500). But in the NFL, relying on rookies doesn't come with the same catch it did a decade ago.

Rookies, injured players and quarterbacks report to training camp for the Detroit Lions today, and while the rest of the squad still has a few days of summer left, there's no denying that the first group of players in the building will be crucial to any success the team has this year.

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First-round pick Jarrad Davis is expected to take over at middle linebacker, where the Lions are entrusting him with calling plays and setting the defense.

His former college teammate, second-round pick Teez Tabor, is one of two rookies who could contribute in a suddenly deep secondary (along with fifth-round pick Jamal Agnew).

And after passing on any significant help at wide receiver in free agency, the Lions are ready to roll with third-round pick Kenny Golladay as their No. 3.

Davis, of course, will draw the most scrutiny of that group given his draft spot and the position he plays. At middle linebacker, he'll take the place of last year's leading tackler, Tahir Whitehead, who moves to the weak side, and he was picked ahead of pass rushers Charles Harris and Takk McKinley, both of whom would help the Lions this fall, albeit in more complementary roles.

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At Florida, Davis was a three-down player who, when healthy, was one of the fiercest hitters in the SEC. The Lions are counting on him to be that and more this year on a defense that, outside of Ziggy Ansah and Darius Slay, is still devoid of playmakers.

Historically, the learning curve for rookie linebackers hasn't been as steep as say quarterbacks or wide receivers, but that doesn't mean Davis is a lock for Taylor Decker-like instant success.

Last year, the Falcons revamped their linebacking corps and turned rookies Deion Jones and De'Vondre Campbell loose as (almost) Day 1 starters. Jones and Campball gave the Falcons a much-needed speed upgrade in the middle of the field, like Davis should do for the Lions, and Atlanta's defense turned into a nice complement to the league's most explosive offense.

But while Jones and Campbell found success as rookies, most of the non-pass-rushing linebackers drafted in front of them did not.

Darron Lee (the 20th overall pick) made nine starts for the New York Jets and showed flashes as a rookie, but he also struggled in pass coverage and graded out as the worst rookie linebacker according to Pro Football Focus.

Myles Jack, coming off a college knee injury, struggled to carve out a role with the lowly Jacksonville Jaguars and had just 24 tackles as the No. 36 pick, and Jaylon Smith (No. 34) and Reggie Ragland (No. 41) missed last year with injuries.

The Lions, led by Decker - who's expected to miss at least the first half of this season with a torn labrum in his right shoulder - had a productive rookie class in 2016 that looks like it should part of the foundation for years to come.

Decker, A'Shawn Robinson and Graham Glasgow all should start this year, and Miles Killebrew will push for major playing time, too.

If Davis and the rest of this year's rookie crop have a similar impact this fall, the Lions might just follow in the Falcons' and Cowboys' footsteps and become legitimate contenders in the NFC.

Contact Dave Birkett: dbirkett@freepress.com. Follow him on Twitter @davebirkett.

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