Mariners name Edgar Martinez hitting coach The Mariners named former DH Edgar Martinez the team's new hitting coach. Former coach, Howard Johnson, was reassigned to the minor leagues By Shawn Krest Jun 20, 2015 at 12:56 pm ET • 1 min read The Mariners announced that former designated hitter Edgar Martinez has been named the team's new hitting coach. Howard Johnson, the team's hitting coach for the first three months of the season, was reassigned to the minor leagues.