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Most of the Detroit Lions' positional battles focus around the defensive side of the football. Here are the top battles in training camp:

1. Strong Safety

Louis Delmas has one safety spot locked up, but the other is up in the air. The Lions signed veteran Erik Coleman for competition in camp, and he might win the job. 

Second-year player Amari Spivey is also an option. He's likely the future at the position, but made his share of mistakes as he was shifting positions in his rookie year. 

Coleman could ultimately win the job with a good camp. Spivey will get his chance down the line. 

2. Cornerback

The Lions have plenty of options at cornerback, but very few sure things. Chris Houston is back after starting last season, as is Nathan Vasher opposite him.

The club also brought in Eric Wright from Cleveland. Alphonso Smith and Aaron Berry are options but have suffered through injuries. 

The Lions desperately need one or two to step up and take hold of the position. Houston is a good bet, and Vasher is a veteran who knows the position and division. Wright has a lot of upside, as does Smith and Berry. 

In the pass-happy NFC North (and NFL, really), the Lions need players to improve inside the system at camp. 

3. No. 2 running back

Second-round pick Mikel Leshoure was slated to fill this role, but he blew out his achilles today and will require season-ending surgery. It's a big loss for a Lions' backfield who was relying on his contributions. 

Leshoure was going to be counted on heavily because 2010 first rounder Jahvid Best isn't suited to be a 25-carry back. He needs relief at points. Now, the Lions will have to scramble something together, and they might look towards free agency. 

Either way, the Lions need to identify Leshoure's replacement and get him into camp (if a free agent). There are plenty available who can still rectify the situation.

Checking in on all the Detroit Lions' offseason moves, training camp problems and positional battles during the preseason. Detroit Lions 2011 Predictions: Latest Analysis as Lions Prepare for Preseason

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The Detroit Lions have three main issues facing them as the progress through camp and into the preseason:

1. Keep Stafford healthy

Everything the Lions want to do on offense centers around Matthew Stafford being on the field. In his first two NFL seasons, he struggled to do that. 

Rarely do you hear about quarterbacks getting injured during camp, as they're given red jersey's that keep them off limits. But once the preseason starts, the mission begins: keep Stafford on the field. 

It's more a game of luck than anything, but the Lions' promising season could go up in flames if Stafford is lost again.

2. Establish the back seven

The linebackers have fallen together nicely for the Lions, as both Stephen Tulloch and Justin Durant should make immediate impacts. Add in Louis Delmas at safety, and the Lions have some nice pieces in the back seven. 

Still, cornerback is largely unsolved, as is the other safety spot. The Lions need players to step up at those positions if they want to compete for a chance at the playoffs. 

Their development should be aided by the Lions font four, who will create a lot of problems for opposing offenses next season. 

3. Establish themselves 

The time is now for the Lions to show the league that they are for real. They ended the 2010 season with a four-game winning streak, but now the team is in year three with the same coaching staff and ready to take the next step. 

The Lions clearly have the talent to win games next season, but half the battle of being a winner is caring yourself like one. 

Detroit needs to believe that they can compete in the ultra-competitive NFC North. That mentality needs to start in training camp and extend into preseason play.

Checking in on all the Detroit Lions' offseason moves, training camp problems and positional battles during the preseason. Detroit Lions 2011 Predictions: Latest Analysis as Lions Prepare for Preseason

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The Philadelphia Eagles spent loads of money on big-time free agents. The New England Patriots traded for once-dominant players who could shine under Bill Belichick. 

But quietly, the Detroit Lions put together one of the better offseasons of any team. 

Their first three draft picks (Nick Fairley, Mikel Leshoure and Titus Young) were solid picks, regardless of the injury situations of the first two. Fairley has a foot issue and Leshoure will miss the season with a torn achilles. 

The Lions kept making impressive moves once the lockout was lifted and free agency began. 

They filled holes at linebacker by signing two athletic playmakers in Justin Durant and Stephen Tulloch. In their leaking secondary, the Lions brought in Eric Wright and Brandon McDonald. 

Again, not headline signings, but the kind of moves that can turn your team from just "good" to "playoff-caliber." 

And I think that's just what these did. Tullouch and Durant are going to be flying around the football with Lions defensive front. There will be a lot of double-teaming going on against the likes of Ndamukong Suh, leaving free lanes for the two to make plays. 

Wright might be another pickup who could make an impact. He was a bust last season but played well in 2009 with the Browns. With an improved pass rush, he could regain his '09 form. 

Overall, the Lions accomplished every franchise's main goal during the course of an offseason: They got better. Their roster is better, the competition is better and the outlook is better. 

A big credit goes to GM Martin Mayhew for the way he's turned this franchise around Post-Matt Millen.

Checking in on all the Detroit Lions' offseason moves, training camp problems and positional battles during the preseason. Detroit Lions 2011 Predictions: Latest Analysis as Lions Prepare for Preseason