A few showed real promise, but needed that first season – for whatever reason – to feel their way through the league. They showed flashes, but now seem poised to take the leap into full-on production mode.
Here are four second-year players ready to break out this season in the NFC North:
Alshon Jeffery, WR: Jeffery played in only 10 games due to a knee injury and fractured hand as a rookie. He finished with just 24 receptions for 367 yards and three touchdowns.
Alshon is a big body and has good speed and should benefit from the more wide-open offense employed by new head coach Marc Trestman. He doesn't have top-end speed, but he controls his body well and should benefit from Brandon Marshall coming off a career year on the other side.
Key stat: 15.3 yards per reception. Only four rookies had a higher average than Jeffery last year.
Offseason: Jeffery missed minicamp with a “slight” tweak to his hamstring.
"[Jeffery] ran a go-route the other day and made a great play out there and just tweaked it a little bit," Trestman told ESPNChicago.com.
"We're just going to be as cautious as we can. We're trying to get out of here with every player being healthy, and keeping our team as safe as we can amidst the competition that you see going on out there."
Nick Perry, OLB: The 6-foot-3, 265-pound Perry was drafted in the first round by the Packers with the idea that he’d make the switch from defensive end to outside linebacker in the Packers’ scheme.
His progression was slower than the Packers might have hoped and he suffered wrist and knee injuries that eventually landed him on injured/reserve after only five starts. He finished with 18 tackles and two sacks.
Perry is getting a shot to start in 2013 with Erik Walden leaving via free agency. The Packers would love nothing more than to see Perry emerge as a force opposite newly re-signed Clay Matthews.
They are relying on young players like Perry to step in and fill the void on defense. Perry’s athletic skills are just too great for him not to make a difference – when healthy.
Key stat: 1.51 seconds. Perry’s 10-yard splits at the NFL Combine, which was faster than some cornerbacks
Offseason: "I've got a foundation under me right now," Perry told the Milwaukee Journal-Sentinel this spring. "There's a lot of things I know now that I didn't know last year.
"I try not to look back, just keep a positive mind. I don't want to fill my head up with something that happened in the past. I'm just trying to stay positive and staying on that road. But I know I have the skills."
When healthy, though, Broyles is just the kind of slot receiver the Lions' offense needs. He had six catches for 126 yards against a good Houston Texans defense the week before he tore his ACL.
Broyles has the unique ability to find open spaces in the middle of the field and quarterback
Broyles participated fully in the Lions’ three-day mini-camp this week, and though he’s not yet 100 percent, looks way ahead of schedule and should be ready for a breakout year in 2013.
Key stat: 14. Broyles had 14 of his 22 catches come within 10 yards of the line of scrimmage, yet he averaged 14.1 yards per catch. He not only finds the open spots but also can get upfield after he makes the catch.
Offseason: “He’s made up some ground over the last two or three weeks. He went from just doing a little bit of routes on air and mixing it into individual period to all of a sudden being able to do just about everything,” Lions head coach Jim Schwartz said.
“He’s still not 100-percent in his rehab, but I think it was important for him mentally to get out here and do this now before we get to training camp.
"We’ve got another six weeks or so before we’re back on the field. He’s still got some ground to cover and things like that, but the fact that he’s already been out here now, I think that sets him up.”
Harrison Smith, S: Some would argue that Smith had a breakout year as a rookie with 98 tackles, one sack, one forced fumble and three interceptions in 16 starts, but he’s only going to get better.
Smith has nastiness about the way he plays the game, and as he continues to develop in the Vikings’ mostly Cover 2 scheme, he's got the potential to be a Pro Bowl-type player. He’s that good.
Key stat: 2. Harrison returned two of his three interceptions for touchdowns. Both came in wins over the Bears and Cardinals.
Offseason: “It’s not so hectic and not so fast,” Smith told Vikings.com of this offseason vs. last. “I know what to expect and I have a higher comfort level.