The NFL free agent period is still a few weeks away, but teams all over the league are doing their due diligence on all the available players and one of the top positions this offseason is on the defensive side of the ball at the linebacker spot.

There are a number of teams with big needs at the position, including the New York Giants, New York Jets, San Diego Chargers, Minnesota Vikings, Buffalo Bills and the Atlanta Falcons. The Jets and Giants both recently cut a number of veteran players, including linebackers such as Michael Boley, Calvin Pace and Bart Scott, meaning they could be two of the top teams targeting free agent linebackers.

This year there are some solid players on the market, but other positions have more depth than at linebacker, including at cornerback and the offensive line. Some of the top options include Brian Urlacher, Anthony Spencer, Scott Fujita, Connor Barwin, Michael Boley, Bart Scott and Chase Blackburn.

Here is a look at some of the top players at the position that are on the market for NFL teams. Sports World Report also looked at the TOP PLAYERS at each position, the top RUNNING BACKS, top LINEMEN, top QUARTERBACKS, top CORNERBACKS, top SAFETIES and the top WIDE RECEIVERS.

Brian Urlacher, Chicago Bears

Urlacher is one of the top linebackers of his generation, but after years of leading the frontlines of the Bears defense it could be time for him to depart Chicago. The 13-year veteran is still a very capable linebacker, but at age 34 he is on the decline of his career. He had a career-low 68 tackles (apart from his 2009 injury season) with two forced fumbles, but he could help shore up the linebacker position for teams like the Jets, Giants or Dolphins. There is a chance he could stay in Chicago, but Urlacher may also feel like it's time to retire.

Anthony Spencer, Dallas Cowboys

Spencer has proven to be one of the most consistent defensive players for the Cowboys over the past few years and he can play in various spots on the field. He recorded 95 tackles and a career-high 11.0 sacks and three passes defended. He can fit into any 3-4 defensive scheme and he has been a healthy player for the bulk of his career, playing in all 16 games in four of his six seasons in the league. The Cowboys could franchise him, but it is unlikely since they need the money to sign quarterback Tony Romo.

Connor Barwin, Houston Texans

The Texans would love to keep Barwin, but they have done a good job of improving the defense over the past few years after losing players like Mario Williams and Demeco Ryans. Barwin could be the next one to go and he would be a solid pickup for many teams looking for a linebacker that can rush the passer. Although he had just 3.0 sacks last season he had a career-high 11.5 sacks in 2011.

Michael Boley, New York Giants

Boley was cut mainly for salary cap reasons and he has been a solid player for the Giants and key contributor to the teams Super Bowl run in 2011. The 30-year-old can provide good coverage skills and leadership at outside linebacker and is coming off of a down season, meaning he could be signed on the cheap. He made 50 of 57 starts with the Giants and had 92 tackles and three interceptions last season. The Jets, Vikings or Bears could come knocking.