NFL Free Agent Signings: Underrated Acquisitions That Will Pay Dividends

We can't forget about the lesser known 2013 NFL free-agent signings that will make an immediate impact.

Reggie Bush signed with the Detroit Lions according to Tim Twentyman of the Lions' official website. And Cliff Avril was acquired by the Seattle Seahawks per NFL.com's Albert Breer.

Obviously, these two guys were great adds as each remain impressive players at their respective positions.

But other solid players joined new teams this week and shouldn't go overlooked.

Tennessee Titans: Shonn Greene, RB

According to Adam Schefter of ESPN.com, the Tennessee Titans brought in Shonn Greene:

The past two seasons Greene has hit over 1,000 rushing yards and he has collected 362 receiving yards in that same span. Not only is this solid production, but Greene was the main back for the New York Jets who didn't have a reliable passing game.

Greene still managed to score 14 touchdowns. Although Tennessee's backfield belongs to Chris Johnson, Greene is a great complement to give the Titans a two-back tandem.

His quick burst is an advantage in shorter down-and-distances, which helps make play action relevant at any time. Inside the red zone, the Titans can present each as split backs. The playbook then opens up to inside counters, traps and screens.

Factor in pass protection for straight drop backs and Tennessee gets more balanced with Greene assisting Johnson.

Kansas City Chiefs: Donnie Avery, WR

Also from Schefter, the Kansas City Chiefs spruced up their receiving corps with Donnie Avery:

Although he didn't make a significant impact with the Titans in 2011, Avery got back on track with the Indianapolis Colts in 2012. Courtesy of Andrew Luck, Avery set career highs in receptions (60) and receiving yards (781).

He's an intriguing get for K.C. because Avery can slice underneath the coverage at the intermediate level and make things happen after the catch. However, the potential to win one-on-one battles deep will stretch a defense to present explosiveness.

The Chiefs are clearly looking to bounce back in 2013 and Avery adds another playmaker to Andy Reid's offense.

Denver Broncos: Terrance Knighton, DT

Needing to bolster the defensive line, the Denver Broncos signed Terrance Knighton per John Elway's official Twitter:

Knighton accounted for 32 tackles, two sacks and two forced fumbles last season.

The guy moves incredibly well for his size, which is also needed for success at the position. He's capable of clogging both A-gaps against the run, applying interior quarterback pressure and drawing double-teams.

Knighton's best year came in 2010 where he logged four sacks, 34 tackles and defended four passes. Therefore, the instincts to react quickly against faster developing plays reside along with the talent to help Denver control the line of scrimmage.

And with Von Miller rushing the outside, Knighton will produce consistently on the inside.