t last month’s winter meetings, Major League Baseball was poised to make two major changes to the sport: A broad expansion of instant replay and elimination of collisions at home plate.

But with spring training only one month away, it’s uncertain whether either will be implemented for the 2014 season. One major reason: The MLB Players Association has yet to give its approval, which is required under baseball’s collective bargaining agreement.

In a Saturday email to FOX Sports, MLBPA executive director Tony Clark said the union’s executive board discussed instant replay expansion and home plate collisions “at length” during its December meeting.

“Without getting into the specifics of those discussions,” Clark told FOX Sports, “I can say that a consensus on both matters was not reached.”

The lack of agreement is somewhat surprising, since it seemed MLB was ready to put the finishing touches on both changes during the first owners’ meeting of 2014 next week in Arizona. Clark’s comments suggest that is not a fait accompli.

Major League Baseball didn’t publicly reveal specifics of the instant replay proposal during the winter meetings, but executives from the commissioner’s office held a two-hour discussion with the league’s general managers and field managers.

Afterward, MLB executive vice president of baseball operations Joe Torre said nothing was set “in stone” because the approval of the players’ and umpires’ unions was required.

The MLBPA agreed to the implementation of some expanded replay — catch/trap in the outfield and fair/foul beyond the bases — in collective bargaining after the 2011 season.