Major League Baseball and its players union have announced a new set of protocols for dealing with concussions, including the creation of a new seven-day disabled list for players with the injury. The new rules include mandatory baseline testing for all players and umpires and new steps for evaluating players who may have suffered the injury and for having them return to action. They will go into effect starting on Opening Day. The new disabled list is in addition to the 15-day and 60-day DLs that already exist for players with injuries.