Entering a big league ballpark will be a bit like going through an airport by 2015.FILE - In this June 11, 2013 file photo, stadium workers use metal detector wands on fans as the they arrive for the baseball game between the Pittsburgh Pirates and the San Francisco Giants in Pittsburgh. The Seattle Mariners announced Tuesday, Jan. 21, 2014, that fans entering Safeco Field will have to walk through metal detectors starting with this year's opener. Major League Baseball has told its 30 teams they must implement security screening for fans by 2015.FILE - In this April 20, 2013 file photo, fans pass through security before entering Fenway Park for a baseball game between the Boston Red Sox and the Kansas City Royals in Boston. The Seattle Mariners announced Tuesday, Jan. 21, 2014, that fans entering Safeco Field will have to walk through metal detectors starting with this year's opener. Major League Baseball has told its 30 teams they must implement security screening for fans by 2015.