NFL players have been given an additional 48 hours to complete voting on a new 10-year contract offer that includes expanded playoffs and an additional regular season game, the players' union said Monday.

"Every vote matters, and we encourage all players to review the materials sent via email in order to make an informed decision," the NFL Players Association (NFLPA) said in a statement.

Voting, which got under way last week, was due to close just before midnight on Thursday.

But the NFLPA said Monday the ballot boxes would now remain open until 11:59 pm on Saturday following a vote of player representatives.

NFL team owners approved the new collective bargaining agreement offer last month, a deal that if approved would start some changes in time for the 2020 campaign, the last year under the current agreement, while others would begin in 2021, when the extension would begin, and run through the 2030 season.

The NFL proposal would add two playoff teams, and two extra postseason games, starting with the 2020 playoffs if ratified. Only the teams with the best record in each conference would be awarded first-round byes, not the top two.

The deal would give the NFL the option to add a 17th regular-season game to the schedule as soon as the 2021 campaign.

Players would stand to make a larger percentage of total NFL revenues by adding the extra game, above 48 percent during the deal, but many players have said they do not want the extra toll upon their bodies at any price.