A source close to the negotiations told ESPN's Karl Ravech the biggest issue is not the number of years, but the amount of money the Cardinals offered. St. Louis' offer would place Pujols in baseball's top 10 in salary, but not in the top five in average annual salary, the source said.

The two sides have not exchanged contract proposals in about four days, sources told ESPN The Magazine's Buster Olney, who first reported that talks had broken off.

"We felt very good about the offer we made," general manager John Mozeliak said.

Sources have previously told Olney that Pujols, who has the right to veto any trade, will not accept any trade going forward.

"We are greatly disappointed at this outcome," Cardinals chairman William DeWitt Jr. said at a news conference. "We will revisit it again following the 2011 season, at which time we will again make every effort to keep him as a Cardinal."

Pujols, a nine-time All-Star, is the only player in major league history to hit 30 or more home runs each of his first 10 seasons -- all with the Cardinals, the franchise he has said in the past he wants to remain with for the rest of his career.

"We're all working together toward a common goal and that is to win a world championship for the city of St. Louis," Pujols said. "The last thing anyone in this clubhouse needs to worry about is what's going to happen to me after the season."

But the sides failed in recent months to reach common ground, raising the possibility the three-time NL MVP may be on the cusp of his final season in St. Louis.

"While both parties were hopeful that an agreement could be reached, a difference of opinion in determining Albert's value simply could not be resolved," Dan Lozano, Pujols' agent, said in a prepared statement.

"The expiration of today's deadline does not eliminate the possibility of Albert returning to the Cardinals in 2012 but simply delays negotiations until the conclusion of the Cardinals' season," Lozano said.

Lozano said Pujols set the negotiating deadline so that he would not distract the organization or his teammates during the season. He said Pujols will not discuss his contract situation with the media in spring training or during the season.

"[Pujols] feels as strongly as ever that this team has the potential to win the World Series. That alone is why he will not permit his contractual situation to become a distraction or take away from his ability to reach that goal," Lozano said.

Pujols will make $16 million this season in his contract's final year, with $4 million of the money deferred with no interest.

Pujols said he doesn't want to negotiate during spring training or the season. The Cardinals say they are open to talks.

"It's not as if he's a free agent at this point," Mozeliak said.

St. Louis said it made an offer at the start of the year and then discussed possible modifications.

"They were lengthy and in depth," DeWitt said of the talks.

Pujols' teammates said Wednesday they can't wait to see him.

"It really doesn't matter to us," said Cardinals pitcher and union rep Kyle McClellan, when asked about the ongoing Pujols contract watch. "It's none of our business. It's none of anybody's business. ... The truth is, I've never been on the mound and thinking of Albert Pujols' contract."

A handful of St. Louis position players were at work ahead of schedule; pitchers and catchers are in camp, and position players aren't required to arrive until Saturday.