The Buffalo Bills relinquished their exclusive negotiating rights with guard Andy Levitre on Friday.

Meanwhile, it remained to be seen whether the Bills would demand a restructuring of the contract of quarterback Ryan Fitzpatrick as the NFL prepared for the start of the free-agent shopping season.

Levitre is the Bills’ top fully unrestricted free agent, and he became free to negotiate with other teams early this morning – as soon as the clock struck midnight – under a new NFL rule. The NFL’s free-agent signing period does not begin until 4 p.m. Tuesday. But this year there is a formal three-day period before the start of the new league year in which teams can negotiate with the agents of all players set to become free agents.

The Bills had no deal with Levitre as of Friday, a sign they are being prudent with their offensive line budgeting. Tackles are a higher priority than guards in both the draft and free agency. Many teams want to be careful about how much money they devote to their interior offensive linemen.

Bills center Eric Wood is entering the final year of his contract, and it’s expected the team will want to keep him in the fold with a big contract. The Bills re-signed right guard Kraig Urbik to a contract in December that pays him about $3.4 million a year.

Levitre will be much more expensive. He’s the top-rated guard in free agency this year and arguably is one of the top 10 players available at any position.

The NFL’s top-paid guard is Tampa Bay’s Carl Nicks, at $9.8 million a year. The fifth-highest paid guard is the Giants’ Chris Snee, at $7.25 million a year. Arizona’s Daryn Colledge has the 10th best guard deal, at about $5.5 million a year.

Levitre never has made All-Pro or the Pro Bowl. But neither has Colledge nor Green Bay’s Josh Sitton, who makes $5.8 million a year. Furthermore, Levitre’s durability figures to be attractive to other teams. Not only has he never missed a start in his four-year, 64-game career, he hasn’t missed a single play in his last 46 games.

The Bills stood about $18.5 million under the NFL salary cap as of Friday, according to News figures. The amount of space they need depends in part on how much free-agent shopping they intend to do.

Fitzpatrick could give them more space under the cap.

Bills coach Doug Marrone has stated Fitzpatrick will compete with Tarvaris Jackson and whoever else the Bills add at quarterback for a starting position.

Fitzpatrick is due to get a $3 million bonus on Wednesday. If he gets that bonus and does not take any kind of pay cut, he would count $10.4 million against the Bills’ salary cap. If he were to be released before the bonus is paid, he will count $10 million against the cap. Fitzpatrick is due to make a base salary of $4.25 million this year.

There are few quarterback options available to teams in free agency. Chicago’s Jason Campbell and Kansas City’s Brady Quinn are the top unrestricted quarterbacks. The top young quarterback who might be available in a trade is Philadelphia’s Nick Foles. The Bills passed on him in the third round of last year’s draft to take receiver T.J. Graham.

While teams are allowed to negotiate with the representatives of unrestricted free agents today, no players may visit a new team until after 4 p.m. Tuesday. And teams may not make travel arrangements for unrestricted free agents until then.