Major League Baseball took a big step toward full-scale instant replay reviews Thursday when the 30 club owners unanimously approved funding for an extensive video system that would allow managers to challenge almost every umpire's call except balls and strikes.

"The clubs are very excited about it," Commissioner Bud Selig said after the owners' quarterly meetings at the J.W. Marriott Grande Lakes.

MLB hopes to institute the system in time for the start of the 2014 season.

However, the plan must also gain the approval of the Major League Baseball Players Association and the World Umpires Association. MLB officials will meet with both unions in January.

Selig had long been opposed to replay and begrudgingly agreed late in the 2008 season to allow home run calls to be reviewed. However, his thinking has shifted in recent years.

"My father always said life is a series of adjustments and I've made an adjustment," Selig said. "There isn't one play or one instance that changed my mind. It has just happened over time. I know we're doing the right thing."

The biggest change from the expanded replay system that was originally unveiled at the last owners' meetings in August at Cooperstown, N.Y., is that managers will get a maximum of two challenges that can be used at any point in the game. The original plans was to allow managers one challenge in the first six innings and two more from the seventh through the end of the game.

MLB chief operating officer Rob Manfred said a final decisions of whether managers get one or two challenges has not been made and will be part of the negotiations with the players and umpires.

The rest of the plan remains basically unchanged, including a manager retaining the challenge if he wins his appeal.

That will likely end most manager/umpire arguments because if a manager disagrees with a reviewable call, his only recourse would be to use a challenge. Managers would not be able to argue a reviewable call in a bid to get it overturned without the use of replay.

About the only situation where a manager could still argue would in situations not open to review, such as defending a player or questioning an improper substitution.

"Pace of the game is important," Manfred said. "We want to be able to do this with as little disruption as possible."