(Jupiter, FL) -- Major League Baseball and the Players Association are continuing their efforts to end the league's current lockout. ESPN reports it was a "productive day of talks" when the sides met multiple times on Sunday. While productive, the union reportedly still feels the sides are far apart on terms for a new collective bargaining agreement. The sides are working to avoid delaying Opening Day, which is scheduled for March 31st. If no deal is reached by the end of Monday, the MLB has made it clear that any games missed won't be rescheduled. That would result in a shortened season for the league.