The Carolina Panthers didn't have a headline-grabbing free agent signing over the offseason. The lack of a big name doesn't mean that their targeted signings won't fill needs and have an impact on the team's success.  

Here's a look at some of their key additions and how they've looked in camp so far: 

RB Mike TolbertSigned on March 19 from the Chargers, Tolbert gives the Panthers a versatile fullback, something the team was lacking last year. Tolbert wasted no time in making his presence known on offense. Coach Ron Rivera said Tolbert made TE Jeremy Shockey expendable, since he can block and catch passes, but also adds a running threat and special teams presence. As if preparing for the explosive Cam Newton-led offense wasn’t hard enough, opposing defenses will now have to account for all the new wrinkles Tolbert presents.

S Haruki NakamuraSigned on March 16 from the Ravens, Nakamura was expected to challenge for a starting safety job and contribute on special teams. He’s rotating in on the first team with Charles Godfrey and Sharrod Martin, and should compete with Martin for the FS job. So far, it’s too close to call. Neither Martin nor Nakamura has slumped or pulled away, and the battle should continue into the preseason schedule.

K Justin Medlock and P Nick HarrisThe Panthers might be replacing both specialist positions this year. They signed Harris on May 7 from the Jaguars instead of bringing back Jason Baker, who finished 32nd in net punting last season. Harris is competing with rookie Brad Nortman. The team also signed Medlock out of the CFL on March 6 to compete with Olindo Mare, who missed two crucial late-game kicks last season. Medlock didn’t miss during minicamps and had the early advantage over Mare. Neither position battle is expected to be settled until near the end of preseason. 

For more up-to-the-minute news and analysis on the Carolina Panthers from blogger Shawn Krest, follow@CBSSportsNFLCAR.