"This is an issue that we've been concerned about for some time," Mariners president Kevin Mather said. "We still have some details to work out, but the bottom line is expanded netting at Safeco Field is going to happen."
The changes could be in place as early as the start of next season. The Mariners close out their current home schedule this Sunday.
The issue of fan safety isn't new in Major League Baseball, but it came to the fore again Wednesday when a youngster was hit by a line drive off the bat of the Yankees' Todd Frazier in the fifth inning of an 11-3 win against the Twins.
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB. This story was not subject to the approval of Major League Baseball or its clubs.