The Detroit Lions went on a small spending spree in free agency. Among the key moves, the team re-signed cornerback Chris Houston and safety Louis Delmas while adding running back Reggie Bush, defensive lineman Jason Jones, safety Glover Quin and defensive tackle C.J. Mosley.

Still, Detroit has plenty of holes on its roster to fill before training camp. Here are the top five needs we've identified heading into the 2013 NFL draft.

1. Defensive end

This is unquestionably the biggest need for the Lions.

Detroit currently has three edge-rushers on the roster, but lack a clear-cut difference-maker. Coming back from last season are Ronnell Lewis and Willie Young. Lewis played just one defensive snap as a rookie in 2012 and Young fell well short of expectations, failing to register a single sack in 15 games.

Jones was a solid offseason addition, but he hasn't been a starter in two years. He has battled through a number of injuries that have limited to 20 games over those two seasons.

2. Offensive guard

On the left side, Rob Sims is arguably the Lions best offensive lineman, but there's an opening on the right side after the team released long-time starter Stephen Peterman.

Currently, it's projected Dylan Gandy, Bill Nagy and Rodney Austin will compete for the job in training camp, but that could quickly change depending on the remainder of the offseason.

The draft offers the Lions a couple ways to improve this spot. First, the team could select one of the top guards in the early rounds, specifically someone like Justin Pugh or Larry Warford at the top of the second round.

The other option would be selecting an offensive tackle with the fifth pick and moving one of the current tackles on the roster, possibly even 2012 first-round pick Riley Reiff, inside.

3. Offensive tackle

After losing Jeff Backus to retirement and Gosder Cherilus in free agency, the Lions are left thin at one of their deepest positions in 2012. Reiff is a logical answer to fill one of the spots, but questions linger about the other bookend.

Corey Hilliard has starting experience, but isn't exactly a long-term solution. The coaching staff also likes Jason Fox, a former fourth-round pick they've developed over the past three seasons, but questions linger about his durability. Additionally, he'll be playing on a one-year contract as a restricted free agent.

4. Wide receiver

When don't the Lions need a wide receiver? Even if Nate Burleson and Ryan Broyles are good to go by the start of the regular season, Detroit needs to replace what Titus Young was supposed to bring to the offense -- someone who can stretch the field with speed and draw coverage away from the other receiving options, whether it's Calvin Johnson or Reggie Bush underneath.

In an ideal world, the Lions would find a receiver with above average return skills, capable of contributing a big play on special teams a few times per season.

5. Tight end

The Lions have two tight ends on the roster, Brandon Pettigrew and Tony Scheffler, both locked into their roles. They also essentially lost two players at the position. The team has not yet made a move to bring back Will Heller and Riley Reiff will no longer be able to play the role he did in 2012 as a reserve.

The Lions need to find a versatile tight end, capable of catching short to intermediate passes, but with an emphasis on quality blocking skills in both the pass and the run.

It's not out of the question that the Lions to select a tight end on the second day of the draft considering that Pettigrew and Scheffler are scheduled to be free agents.

Honorable mention: Secondary depth

The Lions already have better quality depth at safety than last season, but the memory of a patchwork secondary in 2012 lingers. Bill Bentley, Chris Greenwood, Louis Delmas and Amari Spievey are all question marks when it comes to durability, so Detroit will want to make sure it has some additional insurance on the roster.