ATLANTA -- In a move that reflects the negotiating gap between the NFL and its regular officials, league sources told ESPN.com that replacement referees, who begin work with Thursday night's preseason games, have been offered a longer guarantee.

Sources confirmed that when replacement officials arrived at Wednesday symposiums in various cities, they were offered a guarantee of four games at a minimum of $2,000 each.

The original guarantee to the replacements was for two games at $2,000 apiece.

One of the replacement referees, reached at an Atlanta-area airport hotel where one of the training sessions was conducted Wednesday, said he felt that "many" of the substitute game officials were "strongly considering" the four-game guarantee. The replacement official spoke on the condition of anonymity.

"Basically, they said they are very far apart in their negotiations (with regular officials) and there is a pretty decent chance that this thing will go on for a while," the replacement official said. "So they doubled the number of games they're willing to guarantee."

In a related matter, the regular officials said they would not set up picket lines at the six preseason games scheduled Thursday night.

Talks between the NFL and the NFL Referees Association broke off Tuesday with the two sides far apart.