The Oakland Raiders were arguably one of the most improved teams during the 2015 season, and while they didn't make the playoffs last season, they showed strong improvement under first year head coach Jack Del Rio.

The Raiders entered the offseason with the second largest cap space in the NFL, and general manager Reggie McKenzie is wasting no time in acquiring talented players to add to the Raiders roster. The Raiders have reportedly already agreed to deal with free agent offensive lineman Kelechi Osemeli and are looking to add another Super Bowl champion to their roster in Seahawks linebacker Bruce Irvin.

The team and Irvin have reportedly reached an agreement to bring the Seahawks linebacker to Oakland, thus bringing one of the top free agents to the Silver and Black's defense in 2016. Irvin will join former teammate and Super Bowl champion Malcolm Smith in the Raiders defense and brings an immediate presence to Oakland's defense.

The Raiders lost some key pieces following the 2015 season as both Charles Woodson and Justin Tuck decided to retire, but McKenzie and the Raiders front office are doing what they can to replenish their roster, especially on the defensive side of the ball. Irvin was a consistent playmaker during his four seasons in Seattle and is coming off another productive season in which he recorded 38 combined tackles and 5.5 sacks while forcing a fumble.

Irvin is reportedly signing a four-year deal worth $37 million, which includes $12.5 million in the first year. While the Raiders have reportedly landed one of the top defensive and offensive free agents this offseason, they are not done, as they are reportedly targeting Chiefs cornerback Sean Smith in free agency.

The Chiefs are looking to retain the talented corner, but the Raiders are focused on luring him to Oakland this offseason. Smith recorded 45 combined tackles and two interceptions while defending 12 passes during the 2015 season. The former second round pick turns 29 years old prior to the 2016 season and could make a nice addition to the Oakland's secondary.

The Raiders are looking to return to the postseason for the first time since the 2002 season, and they are building a strong roster through free agency that should likely compete and have a chance to win the AFC West division next season.