The new NFL league year begins March 9 at 4:00 p.m., which also signals the official opening of free agency.

While clubs are permitted to contact with the agents of impending free agents beginning March 7, teams can't start signing players until after the New Year, meaning those few days are among the busiest of the year for general managers.

Reggie McKenzie is no different, as last year in the opening days of the new year, he and the Raiders officially signed seven key free agents to the roster – a number that just further shows how drastically NFL rosters can change in a very short amount of time, particularly in the opening days of free agency.

Just days ahead of the onset of free agency, let's look back to the players McKenzie signed in the early days of free agency last year and how their 2015 seasons played out.

Safety Nate Allen (signed March 12, 2015)

The Raiders attempted to sign Nate Allen heading into the 2014 season, but the athletic safety elected to return to the Philadelphia Eagles for one more season.

However, heading into last season, the Silver and Black came calling again, and this time Allen decided it was the right time to move west.

His first season had its ups and downs to be sure – he only appeared in five games in 2015 – however, he did record a game-clinching interception against the Tennessee Titans in Week 12.

The team actually released the veteran safety February 9, only to re-sign him two days later.

Running Back Roy Helu, Jr. (signed March 11, 2015)

The versatile third-down running back was signed to provide a change of pace in the Raiders' backfield heading into 2015, but it just never materialized.

Helu, who joined the Silver and Black after a productive run with the Washington Redskins, battled injury all season and was just never able to get his feet under him and find a rhythm.

While he did record one receiving touchdown, the Bay Area-native caught just nine total passes for 75 yards.

In the nine games he suited up, he also carried the ball 17 times for 39 yards.

Center Rodney Hudson (signed March 11, 2015)

Arguably the jewel of McKenzie's 2015 free agency haul, the athletic center from Florida State proved his worth and then some during his first season with the Raiders.

Hudson started all 13 games he appeared in last season, anchoring a much-improved offensive line for the Silver and Black.

Not only did the group keep Derek Carr clean, providing the second-year quarterback time to operate, they also proved to be maulers in the run game, helping spring Latavius Murray to his first 1,000-yard rushing season – the first the team had since 2010.

Head Coach Jack Del Rio said that Hudson played at a Pro Bowl level in 2015, and he's right, the former Kansas City Chief was impressive last season.

Linebacker Curtis Lofton (signed March 11, 2015)

After spending the previous three seasons in New Orleans with the Saints, Lofton signed with the Raiders heading into the 2015 season.

In his first season in Silver and Black, the veteran linebacker appeared in all 16 games, making nine starts, totaling 45 tackles and one sack.

Tight End Lee Smith (signed March 11, 2015)

While Smith's stats from last season might not jump off the page, he proved to be a valuable asset for the Raiders' offense.

Never heralded for his statistical productivity while he played for the Buffalo Bills, Smith's blocking ability made him a valuable commodity for the Raiders along the offensive line, oftentimes serving as an extra blocker in run packages.

Smith wasn't one dimensional though – he caught 12 passes for 70 yards, including one touchdown, just the fourth of his career.

Linebacker Malcolm Smith (signed March 11, 2015)

Smith was one of McKenzie's earliest signings last season, and while the former Super Bowl MVP didn't garner a lot of fanfare initially, throughout the season he more than proved his worth to the Raiders' defense.

As the offseason program began, Smith found himself on the outside looking in at the linebacker rotation, but as training camp wore on, he eventually earned a starting job at outside linebacker – a job that he wouldn't surrender. 

In 2016, the former USC Trojan started all 16 games for the first time in his career, and also set a career high with a team-high 143 tackles (98 solo) with four sacks, one interception, seven passes defensed and two forced fumbles.

Defensive Tackle Dan Williams (signed March 11, 2015)

The big defensive tackle who spent the first five seasons of his NFL career with the Arizona Cardinals enjoyed a career year in 2015.

Not only did Williams, along with defensive tackle Justin Ellis, anchor the Raiders' defensive line all season, he appeared in all 16 games, making 15 starts, and tallied a career-high 59 tackles, one sack and three passes defensed during his first season in Silver and Black.

In addition to his production on the field, Williams, particularly after the loss of Justin Tuck, also served as a veteran presence on what was primarily a young and inexperienced defensive line.