Allen Park -- The Detroit Lions rookies report to training camp on Thursday and the team's veterans will join them late next week. As we preview camp, we've already looked at:

Key roster battles

Breakout candidates

Players primed for rebound seasons

Today, we'll explore five statistical shortcomings the Lions should look to correct if they want to return to the postseason and compete for the NFC North crown.

14 takeaways

The Lions did a decent job protecting the football last season, turning the ball over just 19 times. Still, the team finished in the red in turnover margin. That's because the defense managed the second-fewest takeaways in the league.

The biggest issue was interceptions. Star corner Darius Slay continued to be productive in that department, snagging three picks, but the rest of the unit contributed only four more.

The team bolstered its cornerback corps this offseason in the search for more playmaking. New nickel Justin Coleman has 19 pass breakups and three interceptions the past two seasons, while Rashaan Melvin, a contender for the outside job opposite Slay, has knocked away a pass per game over the same stretch, while coming down with four balls.

You can still win without turnovers, but they certainly make life easier. Four of the top five defenses at taking the ball away won their division in 2018, including both Super Bowl participants.

26.3 percent pressure rate

You know what helps generate turnovers? Making quarterbacks uncomfortable.

If a defense can consistently pressure the pocket and force opposing passers to rush their throws, it's naturally going to lead to more mistakes. Not surprisingly, this is an area where Detroit struggled a year ago.

While pressure is a subjective measure, the Lions ranked near the bottom of the league by the various entities which attempt to track it. We leaned on Football Outsiders' figure, where the Lions ranked 29th in the NFL.

A big part of the problem was injury-related. Ziggy Ansah should have been leading the charge for Detroit's pass rush, but a pair of shoulder injuries sidelined him much of the year. Romeo Okwara filled in admirably, leading the team in pressures, according to Pro Football Focus, but those 39 disruptions ranked outside the top 50.

Enter Trey Flowers, the crown jewel of the Lions' spending spree in free agency. The longtime Patriot has never posted double-digit sacks in a season, but that doesn't take away from how much he disrupts the pocket. His 64 pressures tied for 13th last season.

53.1 percent in the red zone

Despite what the Chiefs and Rams attempted to make us believe in that wild Monday Night Football shootout last season, scoring touchdowns in the NFL is tough. So when the opportunities present themselves, they can't be squandered.

The Lions squandered far too many in 2018. Averaging a little more than three trips to the red zone, slightly below league average, the offense barely managed to get the ball into the end zone more than half the time.

With a retooled group of offensive weapons, and a system which emphasizes the ground game, the Lions can't afford to be similarly inefficient this year.

45 receptions, 461 yards

The Lions poured significant resources into remaking the tight end position this offseason following last year's debacle. The 2018 group, cobbled together after the team cut ties with former first-round pick Eric Ebron, collectively fell short of matching Ebron's production from any of the previous three seasons.

To address the shortcoming, the Lions used another first-round pick on the position, adding Iowa's T.J. Hockenson with the No. 8 selection. That addition was supplemented by two free-agent signings — Jesse James and Logan Thomas — and another late-round draft pick, Issac Nauta.

On paper, that's a solid group. Assuming Hockenson is a quick study, there's an chance this year's group could double the team's 2018 production.

6.71 yards per pass attempt

Matthew Stafford might not have the strongest arm in the league, but it's definitely among the best. He can make all the throws, and in recent years, he's also made marked improvements in his accuracy. He's completed better than 65 percent of his throws each of the past four seasons.

So what are we to make of last season's dismal inefficiency throwing the football?

Despite completing 66.1 percent of his throws, the second-best mark of his career, Stafford's yards per attempt were his lowest since 2014, dipping more than 17 percent from a year ago. He finished 27th in the NFL, sandwiched between rookie Sam Darnold and Blake Bortles, who was essentially run out of Jacksonville.

The figure is hardly all on Stafford. His arsenal was decimated by injuries and a midseason deal that shipped out Golden Tate, and Jim Bob Cooter's scheme didn't do the quarterback any favors, with a high percentage of throws designed to be thrown close to the line of scrimmage.

The upgrades at tight end, adding veteran receiver Danny Amendola and getting back Marvin Jones and Kerryon Johnson from injury, should fuel improvement. The biggest question remaining is how aggressive will the new scheme, led by coordinator Darrell Bevell, be with taking shots downfield.