ALLEN PARK, Mich. -- The Detroit Lions improved in each of their first three seasons under general manager Martin Mayhew and coach Jim Schwartz, progressing from 2-14 to 6-10 to last season's 10-6 playoff campaign. So, as they moved through training camp this summer, it was fair to ask: What's next?

"Every team wants to be a champion," receiver Nate Burleson said. "But now we just have to prove we can be consistently [good]. That's the most important thing. We're not that team yet that everybody looks at year in and year out and says we're going to be a contender. We don't have the consistency yet to give off that perception to people outside this facility.

"We don't want to be the team that falls back and be the team that makes mistakes. We don't want to be that successful team that ends up shooting ourselves in the foot halfway through the season."

A few days at training camp revealed the Lions are once again genuine playoff contenders, ones with a structure so routine that coaches had the entire scheme installed in three days. Discussion of an embarrassing offseason has faded, leaving the Lions to focus their attention elsewhere.

Mathematically speaking, the next step for this franchise would be a first NFC North title. But the Lions instead have spent the summer working to shore up the flaws that got them bounced from the 2011 postseason.

"Our goal is to make the playoffs," quarterback Matthew Stafford said. "Once you get in the playoffs, you've got a chance to be in it and go win it. You've seen that it doesn't matter whether you win your division or not. It's good to be fighting tooth and nail and trying to find a way to get in. Once you get in, anything can happen. We want to go back to the playoffs and do something when we get there."

THREE HOT ISSUES

Early in the preseason, it appears John Wendling will be the Lions' starting safety. Carlos Osorio/AP Photo

1. Secondary holes: The Lions had one of the NFL's worst pass defenses over the final six weeks of last season, partially because of injuries to cornerback Chris Houston and safety Louis Delmas. Houston has returned healthy, but Delmas had surgery last week on his left knee and might miss the preseason.

Meanwhile, safety Amari Spievey's camp performance has been uneven enough to allow veteran John Wendling to supplant him as a starter. The Lions are also working to find a replacement starter for released cornerback Aaron Berry, and the most optimism-inspiring turn of camp has been the emergence of rookie Bill Bentley.

In all, the project to repair one of the Lions' primary 2011 weaknesses remains a work in progress.

"It really doesn't matter what they look like in practice," Schwartz said. "It's how they play in games. These next … preseason games will go a long way toward determining how we feel about those guys and how they practice every day and things like that, not what they've done in the past. We’ve got some quality guys back there."

2. On-field judgment: The Lions' issues with penalties last season have been well-documented, and players said Schwartz has been much more vocal in practice to discourage such easily preventable mistakes. At one point last week, right tackle Gosder Cherilus was removed from a team drill after jumping offsides.

"If you do have penalties, you're going to get it," Houston said. "He's going to yell at you."

Meanwhile, it was worth noting that rookie linebacker Tahir Whitehead kept his composure when veteran center Dominic Raiola whacked his helmet after getting tripped. Several defensive players surrounded Whitehead to prevent any escalation, but Schwartz was pleased with Whitehead's response and with how quickly order was restored.

"I think that that's a good step, particularly a rookie like Tahir," Schwartz said, "to be able to show restraint and keep focus even when guys were competing. The biggest thing is not letting those things get a hold of you, and I thought that Tahir did a very good job in that situation."

We're not going to declare the Lions a changed team based on one instance when cooler heads prevailed. But camp usually is when the tenor of a team is set. And even if you don't buy that theory, consider it this way: A focused camp where players are concentrating on their assignments is preferable to one where fighting and other chaos breaks the routine.

3. Health at running back: After months of discussion about the potential of a full-strength backfield, the Lions have yet to get Jahvid Best and Mikel Leshoure on the practice field together. Best remains on the physically unable to perform list, still not cleared to practice, and Leshoure has missed most of camp because of a strained hamstring.

Leshoure is expected to return to practice next week, but, for now, the Lions' most likely Week 1 starter is veteran Kevin Smith. In many ways, Smith is an ideal option when a team's top two running backs are sidelined. He keeps himself in excellent condition and once again showed in camp that he is well-versed in the Lions' offense.

REASON FOR OPTIMISM

In this era of NFL passing efficiency, any team with a quarterback like Stafford, a receiver like Calvin Johnson and a cast of complementary players at tight end (Brandon Pettigrew and Tony Scheffler) and receiver (Burleson and Titus Young), will be competitive. Just as significant to the Lions' hopes, however, is the consistency of their program.

QB Matthew Stafford & Co. have developed some consistency that should benefit the Lions this year. Tim Fuller/US Presswire

Like Schwartz, offensive coordinator Scott Linehan and defensive coordinator Gunther Cunningham are entering their fourth seasons with the Lions. Special-teams coordinator Danny Crossman joined the team in 2010. That means the Lions have to teach their scheme only to the handful of newcomers they welcomed onto their roster and can spend more of training camp focused on higher matters.

"It's tough for a rookie, probably, to jump in," Stafford said, "but the whole playbook is in about three or four days. We have a lot of returning starters who know what to do, and it's on the rookies to pick it up along the way."

Schwartz noted that there are always new wrinkles to work on and adjustments to make, but added: "Our first day of training camp, if we had to go play a game, we probably would have been able to call an entire game on offense, defense and special teams. It gives you a little more leeway. You don't have to start over and you don't have to put things in."

REASON FOR PESSIMISSM

Detroit is a good, playoff-caliber team that plays in what might be the NFL's toughest division. Nothing I saw at training camp pointed to anything other than continued progress toward elite status. The Lions' biggest problem is that they will fight for a playoff-caliber record in a division that contains two similar teams, the Packers and Bears.

The Lions are 2-10 over the past three seasons against the Packers and Bears. Conventional wisdom suggests they will have to beat out at least one of those teams in the NFC North standings to earn a second consecutive playoff berth.

OBSERVATION DECK