NFL Trade Speculation: 7 Biggest Holes Playoff Contenders Should Fill

Just because the NFL completed the 2012 draft, it does not mean teams are done making changes to their rosters for the upcoming season.

And for those of you who may not have known, there are free agents still on the market to be had, possibly at low-rent prices.

The period between now and the start of training camp could be described as "down" time or "assessment" time for teams who still need to find the missing pieces to their roster puzzle in order to make a real splash in the regular season.

Whether it is a key reserve or a starter on defense, these teams could trade for players and still make a huge difference in terms of strength of their roster strength.

When teams start to falter, they tend to crumble quickly. Just ask the Indianapolis Colts. It wasn't just the loss of Peyton Manning. These teams need to find the right players who can help keep their franchises near the top.

New England Patriots: Running Back

I still think this is a team that needs another running back. Actually they "definitely" need another runner in their backfield.

They hosted Colts RB Joseph Addai earlier this month and signed him to a non-guaranteed contract, according to rotoworld.com. The Pats could still be looking to sign a free agent left in the pool or trade for a top reserve back.

Danny Woodhead is a good all-purpose player, but he is not the type of guy to carry the load full time and Stevan Ridley is not going to make teams quake in their boots.

If Addai makes the team, then he could be the workhorse they need. If not, the Patriots had better have a backup plan.

Pittsburgh Steelers: Offensive and Defensive Line

The Steelers are still a pretty good team, but age may start to creep up on them. Could this team still use a few younger players or key veterans to solidify the offensive and defensive lines?

Stacy Andrews is available in free agency and could fit in at tackle. They could also look to someone like Tim Bulman, a defensive tackle who was in Houston last season.

Pittsburgh always does a great job of drafting players who can come right in and play like David DeCastro on the offensive line. But like all teams at some point, age catches up with them and the Steelers need to plan for the future.

Chicago Bears: Wide Receiver

I believe the Bears will be a playoff team this season if they can find more pass catchers for the offense.

The one downfall of this team has always been its receiving corps. While the team did trade for Brandon Marshall, he is not the only person who should be counted on to make the unit better.

This team needs another pass catcher to spread the field and give Jay Cutler another target.

Green Bay Packers: Running Back

This may be a case of another team that will rely on the arm of its quarterback to get to the Super Bowl. Granted, the Packers are more talented than the 1984-85 Miami Dolphins, but the running game still needs work.

James Starks will more than likely go into camp and the season as the starter, but this is a true "pass-first and pray the running game will get you some yards" team.

Aaron Rodgers has some great weapons to choose from when trying to find someone open, but I have always felt if you go to the well too often you eventually come up dry.

Teams will eventually figure out the Packers and their offense. Green Bay must find a runner to open up the passing game and keep defenses honest.

Dallas Cowboys: Pass Rush

DeMarcus Ware is still one of the best defensive ends in the business and one of the NFL's most feared sack artists.

Jay Ratliff and Marcus Spears also play well on the defensive line, but this team needs more speed rushing and pressure from the outside.

Dallas had a great offseason signing Brodney Pool and Brandon Carr, two much-needed defensive backs in free agency, and then trading up to select the best cover cornerback in the draft, Morris Claiborne.

For the team to reach the postseason, Dallas must find more consistency on the line and in the linebacking corps. The back line seems to be fine and should not be an issue for years to come. The other two areas could still be a concern.

I thought for sure this team would look to take a pass-rusher (Courtney Upshaw) or lineman (Michael Brockers) in the first round.

Cincinnati Bengals: Wide Receiver

The Bengals limped into the playoffs last season, won their first postseason contest and then bowed out. The team then took measures in the draft by adding Mohamed Sanu of Rutgers and signing free-agent rookie Marvin Jones of California.

Was it enough?

Last year, rookie A.J. Green was a sensation and Andy Dalton proved to be a real star behind center. This team needs to move forward.

The defense may have gotten stronger this year and now with additions like Kevin Zeitler on the offensive line, Dalton must have more weapons to use in his game plan.

Did the Bengals do enough to help the second-year quarterback?

Baltimore Ravens: Youth on Defense

The Baltimore Ravens have been the heart and soul of this team since its Super Bowl victory. Now the unit that has held the team together could be the first thing to fall apart.

Ray Lewis returns, but he is not getting any younger. Rumors were raised about retirement after an injury-plagued season.

Terrell Suggs tore an Achilles tendon in the offseason and is all but lost for the season. Ed Reed is getting older in the secondary and the team also lost Jarrett Johnson to free agency.

Baltimore may have struck gold when it drafted Courtney Upshaw with its first pick (second round). Upshaw can play on the line and in the linebacking corps and could be the heir apparent to Lewis.

Some teams just get that lucky. But youth needs to be served on this team, much like the Steelers, whom they play twice every season.