Mariners spokeswoman Rebecca Hale said the new security measure complies with Major League Baseball's mandate that all teams implement a screening program by the start of the 2015 season.
Hale said fans at Safeco Field will pass through walk-through magnetometers while their tickets are being scanned. Devices are being installed at all public entrances. Those who do not wish to pass through a metal detector will have the option of being checked with a hand-held device.
Major League Baseball has been working with the Department of Homeland Security to elevate and standardize security practices across the game. The metal detectors are in addition to bag checks that are conducted at all MLB ballparks.
"Fan safety and security is our top priority. The Mariners and Major League Baseball are keenly aware of the current security environment at public events. We believe this step is necessary, poses minimal inconvenience, and ultimately will serve the best interests of all fans," said Sylvester Servance, Mariners director of security.
Metal detectors will be installed at Safeco Field's Left Field Gate this week and will be operational for FanFest Jan. 25 and 26.
"We think it's important to get started now with staff training and to familiarize the public with what they can expect this season. We don't think there will be any major problems moving fans through the gates," said Servance.
The Mariners will continue to enforce the longstanding policy that allows bags, backpacks and purses as long as they are not larger than 16 inches by 16 inches by 8 inches. All bags, including women's purses, will continue to be subject to inspection at ballpark gates.