Detroit Lions training camp preview: OL

For two weeks, we’re previewing the Detroit Lions entering training camp, which begins at the end of July. A reminder – unless a player is an entrenched starter, so much of what will happen during the next month or so will be entirely fluid as players attempt to make an NFL roster.

Position: Offensive line

Starter: Tackles – Riley Reiff (LT), LaAdrian Waddle (RT); Guards – Rob Sims (LG), Larry Warford (RG); Center – Dominic Raiola.

Depth (in training camp): Tackle – Corey Hilliard, Cornelius Lucas, Michael Williams, A.J. Dalton. Guard – Rodney Austin, Travis Swanson, Alex Bullard, Darren Keyton, Bryce Quigley, Garrett Reynolds. Center – Swanson, Austin.

Likely roster spots: Tackle – 4, Guard – 3-4, Center – 2.

What to expect in camp: The Lions return all five starters from their offensive line from 2013, something that is key for continuity, familiarity, blocking calls and tandem blocks. This was also one of the top lines in the league last season, blocking for a 1,000-yard rusher (Reggie Bush). It also kept quarterback Matthew Stafford mostly upright throughout the season.

Yet of the five slots, only three starters are likely guaranteed entering the season. Warford emerged as one of the top rookies in the league last season and was extremely reliable. Raiola returned for another season after one of the best seasons of his career at center. Reiff should also end up as the left tackle for the second straight season.

Waddle – one of the biggest surprises on the Lions last season – will end up competing with veteran Hilliard at right tackle. While both will make the roster, Hilliard might push Waddle more than expected. At left guard, Sims missed a lot of the team drills during the spring recovering from injury and Austin filled in. While Sims should win that job, Austin could make a strong push to unseat the veteran.

Hilliard, Austin and Swanson -- a rookie -- are going to be the key backups. It will be interesting to see if any of the younger players behind them can steal a roster spot. Lucas, an undrafted free agent tackle who could make the roster, is an intriguing prospect. The addition of Reynolds this week should put some pressure on Austin throughout camp as Reynolds is an established veteran who started 10 games for Atlanta last season.

If Austin can't make the jump the staff is hoping for, he could be out of a job. The other wrinkle with Reynolds' signing is if the team doesn't have confidence in Sims continuing a high level of play. Reynolds' signing could be insurance based off that in the preseason since Sims missed time in the spring.

Bullard can play any spot on the line and would be a good practice-squad candidate if he can continue to show that versatility.

What Detroit needs to see: More of the same from last season. If the starting group shows the same sort of connectivity from a year ago, the five starters will likely remain together for one more season before Sims and Raiola become free agents in 2015.

Among the things to watch -- if Raiola, at 35, can build on last season’s resurgence; how Sims rebounds from his injury; and if Warford and Waddle will have sophomore slumps.

Unlike many other positions, it is difficult to tell how good an offensive line will be until the season starts. At this point a season ago, nobody could have predicted Warford being of the league’s top rookies or Waddle turning into a competent starter so quickly.

Depth is going to be a key here as well. Remember, Waddle began the season as the team’s fourth tackle and he only played after injuries to Hilliard and the since-departed Jason Fox.