The way the NFL conducts free agency is straightforward. Once a player’s contract is up, he’s eligible to sign with the team of his choice.

There’s only a small loophole where a player’s former team can choose to match a contract the free agent signed with another team, forcing the player’s hand.

Packers fans experienced the highs and lows of this loophole last week when Green Bay signed Bears cornerback Kyle Fuller to a four-year deal. Hours later, Chicago matched the contract and Fuller remained with the Bears.

Nearly thirteen years ago, the Packers found themselves on the other end – watching division rival Minnesota try to steal away defensive lineman Aaron Kampman.

The Vikings tried to sign the entire Packers defense in 2005

Before the offseason began, Green Bay removed Mike Sherman from his post as general manager and hired Ted Thompson from the Seattle Seahawks front office.

Thompson had his work cut out for him that offseason, as the Packers were already over the 2005 salary cap before adding a single free agent or rookie through the draft.

Add in 35-year-old quarterback Brett Favre was beginning an annual tradition of contemplating retirement and an embarrassing playoff loss to the Vikings at Lambeau Field to end the 2004 season, too.

Thompson not only declined to re-sign either of the team’s star offensive guards, but also released star safety Darren Sharper. Sharper promptly signed with the Vikings.

Minnesota wasn’t quite done adding Packers defenders, though. Days after signing Sharper, the Vikings inked restricted free agent and Green Bay defensive lineman Aaron Kampman to a one-year, $1.2 million deal.

The Packers had seven days to either match the terms of the contract and keep Kampman or receive a fifth-round draft pick from the Vikings for the lineman.

How did the ascending Aaron Kampman fit into a new defensive scheme?

Looking back, it seems like it would have been a no-brainer for Thompson and the Packers to keep Aaron Kampman in the fold for the 2005 season. He started 32 of the 40 regular season games in his first three seasons and finished second on the team in sacks with 4.5 in 2004, and was certainly an ascending playmaker.

If the Vikings truly signed Kampman just to spite the Packers, they did a good job covering their tracks.

“When I went there for my visit, they told me how much they liked Kampman,” Sharper told Packers reporter Rob Demovsky. “When I came back, I told him how much they really liked him. It’s really interesting. And now they signed him. They like him a lot and he can help us a lot here.”

One factor in the Packers’ decision to keep Kampman was the team’s defensive scheme. While no longer the team’s general manager, Mike Sherman was still the head coach. He removed defensive coordinator Bob Slowik, replacing him with Jim Bates.

Bates brought with him a scheme that worked best with speed rushers on the edge, and speed was not Kampman’s top attribute. Some inside the organization considered Kampman as a rotational player or even a backup under Bates’ system.

If Green Bay felt Kampman was not going to be productive playing for Bates, why not let him go and receive a fifth-round pick in return?

Thompson and the Packers take all seven days to decide Kampman’s fate

Shortly after the news broke of Kampman’s offer sheet with the Vikings, Thompson made a statement. "Our plan now is to take some time, to study the offer sheet to determine what is in the best interest of the Green Bay Packers," the general manager said.

With no track record of how the team’s new general manager would respond, Kampman and his agent Neil Cornrich viewed the situation as a win-win. Either Kampman stayed in Green Bay and continued to play for a team and community he enjoyed, or he went to a team in Minnesota bent on adding talent at all costs.

"It is a very positive moment in Aaron’s career," Cornrich said. "It’s very rewarding. He considers himself in a win-win situation."

Ultimately, the Packers decided to keep Kampman. The two sides worked on a long-term contract, but were unable to come to an agreement. Hours before the Vikings offer became official, the Packers officially matched the offer and Kampman remained in Green Bay.

"He's been a good player here," Thompson said after the deadline passed. "He's a great kid. He's great in the locker room. He plays hard. He's the kind of person that you want around your organization."

Almost exactly a year later, Kampman signed a four-year, $21 million dollar contract with the Packers, a big upgrade over the $1.2 million dollar tender he’d received in the 2005 offseason.

In the four years he played in Green Bay after Minnesota’s offer, Kampman recorded more than 40 sacks and made the Pro Bowl twice, a tidy sum for a player once only thought to be worth a fifth-round pick.