Like a lot of people, Vikings backup quarterback Tarvaris Jackson only recently began to understand the consequences for NFL players in the likely event of an uncapped year in 2010.

"It kind of caught me off-guard," Jackson said. "I knew about the uncapped year. But I didn't know about going from four years to six for unrestricted free agency."

That's a big deal, not to mention terrible timing for a four-year veteran such as Jackson.

"Especially for me," Jackson said. "I'm kind of to the point where I need to go somewhere now where I can play, if the opportunity presents itself. At least have that option. That's the main part. To have that option. I'm not saying I'm trying to get out of here, but if I had an option to choose, or if there was an opportunity a team wanted to give me, it would be good to have that available."

When the owners opted out of the current collective bargaining agreement (CBA) in May 2008 and talk shifted to a 2010 season without a salary cap, the general perception was the players would benefit greatly. NFL owners would unleash their inner Steinbrenner and money would gush into the players' bank accounts.

"I think early on, players were thinking, 'Oh, that's great. More money for the players,'" said linebacker Ben Leber, the Vikings' alternate union representative. "Now, players realize there are a lot of drawbacks. There's going to be a lot of turmoil because really only the top 5 or 10 percent of free agents are really going to get paid. But as much as we want to get a deal done [by March 2010] to avoid an uncapped year, we also want to get a fair deal."

Besides requiring two additional years of service for unrestricted free agency, teams also would be able to use an additional franchise or transition tag. And with no salary cap floor in place, teams wouldn't be required to spend a minimum amount on players, as they are now.

"The guys before us worked so hard to get free agency," Leber said. "Of course, after four years you want to reap the benefits of free agency. Going to six years affects a lot of guy's futures. With injuries so prevalent in this game, a lot of guys could get hurt and miss their only opportunity at free agency."

Vikings defensive end Ray Edwards is the perfect example of a guy who stands to lose a ton of money in an uncapped year. Now in his fourth season, he already has a career-high 5 1/2 sacks during what's shaping up to be a breakout season on a Super Bowl contender.

With no new CBA, Edwards will be a restricted free agent in 2010. Asked if that would take a lot of money out of his pocket, Edwards said: "Absolutely it would. But I can't worry about that. ... We have the pieces in place to make a run here. I have to keep playing at the top of my game and not worry about all that other stuff."

Backup offensive tackle Ryan Cook also is in his fourth year with a contract that ends after this season. He lost his starting job at right tackle and could benefit from changing teams.

"I think any time you can become a free agent," Cook said, "you want to become a free agent."

Most players, if not all, would agree.

In Jackson's case, he's the backup to 40-year-old Brett Favre on a team that looks to clinch its division early. In other words, he could have a chance to play some extended minutes down the stretch. Under normal circumstances, that would be an opportunity for a young, moderately experienced quarterback -- he's 10-10 as a starter -- to showcase his skills heading into unrestricted free agency.

"I'd be lying if I said I haven't thought about [playing somewhere else]," he said. "It's hard to say if that would be better for me. This is all I really know. And, hopefully, we'll win the Super Bowl. We got a great chance of winning one, so I'm enjoying that. But, obviously, you want to play, and I'm not playing."

Mark Craig • mcraig@startribune.com