FOXBOROUGH, Mass. -- The NFL players' union has advised its members to prepare for a lockout it expects to come in March, telling players to save their last three game checks this year in case there is no season in 2011.

In a letter to the players that was seen by The Associated Press, NFLPA executive director DeMaurice Smith said the union had an "internal deadline" for agreeing to a new collective bargaining agreement.

"That deadline has now passed," he wrote. "It is important that you protect yourself and your family."

The letter was dated Wednesday, and copies were strewn across a table in the New England Patriots locker room during the media availability on Saturday.

After a reporter asked players about the letter, a Patriots spokesman flipped the copies face-down.

NFLPA spokesman George Atallah declined to elaborate on what effect the passing of the self-imposed deadline would have on negotiations, saying the letter was an "internal communication."

NFL spokesman Greg Aiello called the union's deadline "disappointing and inexplicable, especially for fans."

"We hope this does not mean the union has abandoned negotiating in favor of decertifying and litigating," he said. "We are ready to meet and negotiate anytime and anywhere. But it takes sustained effort and shared commitment to reach an agreement. One side can't do it alone.

About an hour after telling the AP, "We don't comment publicly on our internal communications with players," Atallah did just that on Twitter.

"Today's memo to NFL players was an internal deadline to prepare, not for CBA negotiations," he wrote, following up with two more tweets: "The NFL knows that we have exchanged correspondence and met regularly," and "To spin this as an end to the NFLPA's negotiating is dumb. Perhaps the outrage can be directed towards preventing a lockout."

The NFL has not missed games due to labor strife since 1987, when owners responded to a player strike by continuing the season with replacement players. But the prospect of a lost season in 2011 intensified when owners opted out of the collective bargaining agreement in 2008.

Smith has said that he believes the owners opted out with the goal of locking the players out. The NFLPA's home page features a "Lockout Watch" that counts down the days, hours, minutes and seconds until the CBA expires on March 3.

The one-page letter on NFLPA stationery said the union expects the lockout on March 4, and that players should work with their advisers to prepare for an impending lack of income.

It also said the league threatened to cancel the players' health insurance.

The union said it is filing a grievance to contest a cancellation of health insurance, citing a section of the collective bargaining agreement that states: "Players will continue to receive the benefits provided in this article through the end of the Plan Year in which they are released or otherwise sever employment."

Patriots offensive lineman Matt Light, one of the team's player representatives, said players understand the nature of the business but the threat to cancel health insurance is different.

"You're going to cancel somebody's health insurance and maybe they've got a baby that's due in the offseason?" he said. "Yeah, it gets personal."

Aiello said that there would be no interruption of health care, because of the federal COBRA law that allows employees to continue coverage at their own expense.

"This means that no player or family member would experience any change in coverage for so much as a single day because of a work stoppage," he said. "The union surely knows this and there is no excuse for suggesting otherwise."

Light said he is doing his best to educate his teammates on how to prepare.

"They've got to look at it like they're going into a period in which they are going to change their financial situation," he said. "Nobody knows what's going to happen. But if you're going to go a year without getting paid, you need to prepare accordingly."

Under the deal agreed to in 2006, the players get 59.6 percent of designated NFL revenues. The owners opted out of that deal beginning next year, arguing they have huge debts from building stadiums and starting up the NFL Network that make it impossible to be profitable.

The two sides met last month and said they made "some progress" on proposals involving an 18-game regular season and limiting offseason workouts.

Players have taken their case to the public in recent weeks, briefing Congress on the job loss and other economic impact of a lockout and even drafting letters for lawmakers to send to the league.

Using many of the same studies the NFL relies on when trumpeting public subsidies for new stadiums, an economist commissioned by the union estimated an average of about $160 million in local spending and 3,000 jobs would be lost in each league city if the full 2011 season were wiped out.

The NFL called the figures "a fairy tale."

New England linebacker Tully Banta-Cain said he was already squirreling away his savings in case of a lockout. Banta-Cain said he was also working on his outside businesses, which include a clothing line and a music label.

"I'm trying to prepare," he said. "And I'm trying to establish my off-the-field businesses and make sure I can make money in the offseason."

Information from The Associated Press contributed to this report.