A member of the Washington Nationals grounds crew works the field after MLB baseball workouts at Nationals Park, Thursday, Oct. 2, 2014, in Washington. The Washington Nationals play the San Francisco Giants in the National League Division Series starting Friday. (AP Photo/Alex Brandon)
(AP Photo/Alex Brandon)

Anyone attending a game at Nationals Park this season will head through a magnetometer, or walk-through metal detector, before heading through the turnstiles. The screenings are a substantial addition to security measures that already included bag checks and hand-held metal detectors.

In 2013, Major League Baseball asked its teams to implement a mandatory screening program — by hand-held detectors or magnetometers — by opening day 2015. Some teams were able to implement those measures gradually, but the Nationals waited until the offseason to make the changes needed to house the walk-through magnetometers, according to team spokesperson Jennifer Giglio.

Major League Baseball spokesman Michael Teevan said the league gave teams advance notice, aware that the changes would require adjustments to their game-day procedures. Teevan said the league-wide screening program is a product of MLB’s work with the Department of Homeland Security, and that it has been implemented elsewhere with little inconvenience to fans. He estimates two-thirds of the league’s teams use walk-through metal detectors.

Teams are expected to pay for the increased security measures, though last year the commissioner’s office distributed funds to each club intended to help cover the costs.