With the NFL lockout finally over and teams looking to fill roster needs before training camps begin this weekend, a frenzied run on free agents has begun.
The 25-year-old Johnson, who had a breakout season in 2010 with 11.5 sacks, was one of the premier free agents in this year's class, attracting serious attention from the Atlanta Falcons, the Cleveland Browns and a number of other teams.
Carolina has gotten off to a good start in this hectic free-agency period, but they have more work to do in order to improve on last year's league-worst 2-14 record.
The Panthers have talent at a lot of positions, and they are only a few players away from at least competing in the tough NFC South.
Here are four players at the weakest positions, quarterback, wide receiver, defensive tackle and safety, that the Panthers should consider signing to help them back to respectability.
The only quarterbacks under contract right now for the Panthers are Jimmy Clausen, who struggled (to put it nicely) after being handed the starting job in Week 3 last season, and fellow second-year QB Tony Pike, who completed just six of 12 passes in 2010.
Matt Moore began last year as the starter, but he accounted for almost three times as many turnovers 14 as touchdowns five and had an abysmal 55.6 passer rating. Moore is now a free agent.
It is clear to everyone involved that the Panthers have this year's No. 1 overall draft pick, Cam Newton, in mind as the future at QB. But history has shown (for the most part) that young quarterbacks need a learning period of about one year behind an established veteran.
The Panthers do not have that veteran, which is why they need to look to the free-agent market. There are a few interesting prospects out there, most notably Matt Hasselbeck, who just announced he would not be returning to the Seattle Seahawks.
Hasselbeck's performance has declined a bit over the past few years, but he showed in the Seahawks' opening-round playoff upset of the defending Super Bowl champion New Orleans Saints that he can still get it done.
The Panthers may not want to spend the money necessary to sign Hasselbeck, as there are definitely more than a few teams interested in his services. But they have some cash to spend after cost-cutting last summer, and a proven class act such as Hasselbeck is exactly the kind of player Newton needs to show him how to go about his job.
My gut feeling is that any of these players, who are certainly on the down-slope of their careers, would jump at a guaranteed chance to start and play with offensive weapons like Steve Smith, Jonathan Stewart and (hopefully) DeAngelo Williams.
Right now, Steve Smith is far and away the best wide receiver the Panthers have. He publicly clashed with Jimmy Clausen last year, and he has not made it clear whether or not he will be happy in Carolina in 2011.
There is a way for the Panthers to make sure Smith stays happy. He is one of the best three players the Panthers have ever had, and they owe him at least that much. Plus, a happy Smith is a productive Smith.
He was at his best when he had a big possession receiver opposite him (Muhsin Muhammad), and Malcom Floyd is the definition of a big receiver at 6'5" and 225 pounds.
The Panthers have a bevy of young receivers that the previous coaching staff were hoping might become productive, but so far none of them have. Signing Floyd would provide whoever is playing quarterback with two dangerous options, which Moore and Clausen did not have last year.
Defenses would focus on Smith, because they knew no one else could hurt them in the passing game, and that allowed them to clamp down on the running game as well. A second viable receiver would open up the entire offense, and Floyd would be able to come in and start right away.
Quarterback and wide receiver are the two offensive positions most in need of help, and the rest of the offense is surprisingly talented considering how bad they were last year.
The offensive line will be decent, but one of the deepest positions is running back, where Jonathan Stewart and Mike Goodson have established themselves as productive young players.
DeAngelo Williams has been a great player for his time in Carolina, but he is already 28 and will command a hefty price tag this week. If the Panthers can afford to re-sign him and also address their bigger needs, great. If this is not the case (which I find likely), Stewart and Goodson are still a fairly promising duo.
If you've never heard of Seattle Seahawks defensive tackle Brandon Mebane, good. Let's keep him on the down-low until the Panthers can sign him.
Mebane is entering his fifth year in the league after a solid career at California, and he has flown under the radar of most NFL fans because his numbers aren't eye-popping and the Seahawks' run defense has been less than overpowering.
While that doesn't sound too promising, he is only 26 and supposedly has a great work ethic. He might be a bit of a long shot, but he shouldn't be too expensive, and the investment could pay off in a big way.
The Panthers have a number of underwhelming names at defensive tackle and, in a worst-case scenario, Mebane would just become another one of those.
However, the possibility of Mebane becoming an effective run-stopper who takes pressure off the Panthers' talented defensive ends is too exciting to pass up.
The Baltimore Ravens' Dawan Landry had a superb rookie season in 2006, notching 69 tackles, three sacks and five picks for 101 return yards and a touchdown. He suffered what could have been a career-ending spinal concussion injury in his third year, but came back strong in 2009 and 2010.
The Panthers have not had a game-changer at safety since Mike Minter, and Landry brings that potential. Although they signed Kevin Payne, that still leaves them with only four safeties on the roster, and I doubt any of them will do very much.
Landry should at least be given a look by Carolina.
A playmaker at safety would be a great boon to this Panthers' defense, which wasn't horrible last year, even though they were missing Thomas Davis and Julius Peppers had just left for Chicago. The offense was the main culprit in the Panthers winning just two games. They scored only 12.3 points a game, which was last in the NFL.
The linebackers will be one of the best units in the league, assuming the front office locks down Thomas Davis, and we have already addressed the defensive line.
With new head coach Ron Rivera, a potential franchise quarterback in rookie Cam Newton and the return of players like Thomas Davis and Jeff Otah from injury, the Carolina Panthers can only improve on their pathetic 2-14, 2010 performance.
The signing of any combination of the players I've mentioned would certainly help in that endeavor.
Carolina signing all of these players (or the Panthers making this much of a splash in free agency at all) is not very likely considering their history, but you never know with a rookie head coach.
If everything goes according to plan, I could see this team, with these additions, winning seven or eight games. Don't laugh, we've seen it before.
The 2001 Panthers, one of the worst NFL teams of all time, went 1-15. The next year, with a new head coach, they went 7-9, and the year after that, they came within a John Kasay kickoff out of bounds (and some Tom Brady heroics) of winning the Super Bowl.
I know that's not likely to happen again, but is six or seven wins and a return to respectability too much to ask, especially considering what the Panthers put their fans through last year? I don't think so.
The Panthers will need some good luck for that to happen, but these free agent moves would be a good step toward making their own luck.