The Oakland Raiders need help on defense. Jack Del Rio's unit finished this past season ranked No. 22 in both yards allowed per game (363.6) and points (24.9). They also tied for the eighth-most rushing touchdowns allowed (12) on the season while allowing 4.1 yards per carry to opposing ball-carriers. Khalil Mack can't do everything for these guys. Lucky for Oakland, general manager Reggie McKenzie must spend at least $41 million in free agency this offseason to reach the NFL's salary floor and will have a total of roughly $70 million to play with, so potential improvement is not that far out of reach.

For the Raiders, who suddenly look like a team on the come-up, a splashy big name free agent acquisition would help their reputation and the state of their roster. Similarly, a low-risk, high-reward addition could prove beneficial as well. So why not target a player that fits both criteria?

Buffalo Bills defensive end Mario Williams has changed his tune and said he's open to a pay cut to remain on Rex Ryan's squad. However, should the Bills feel like now is the time to part ways, Williams would be an intriguing free agent. His health and effort in 2015 left a lot to be desired, but the four-time Pro Bowler is just one season removed from posting 14.5 sacks. Motivated and healthy, Williams has a lot left to offer and the Raiders would be wise to at least keep an eye on the situation.

"Assuming the Bills are going to release the 2006 No. 1 pick, Williams would be a good fit for the Raiders, who are losing Justin Tuck to retirement," Bill Barnwell of ESPN.com wrote. "They already have a monstrous pass-rusher in Khalil Mack, but there are concerns about the long-term health of 2015 second-rounder Mario Edwards, who has a "possibly genetic" issue with his neck that could jeopardize his long-term future. Even if Edwards can continue his career, the Raiders could get enough out of Williams as a three-down player to justify giving him a hefty salary on a two- or three-year deal."

We'll keep you posted as Williams and the Bills continue to figure out their "it's complicated" relationship status.