sentences:  He was part of the Mariners' bullpen to start the season and did not pitch until the club's fifteenth game, making him the last member of any team's opening day roster (who was not injured or demoted to the minor leagues) to appear in a game.Iwakuma later became an effective member of the Mariners' pitching staff, pitching in 30 games (16 starts and 14 relief appearances), going 9–5 with two saves and a 3.16 earned run average.On November 2, 2012, Iwakuma agreed to a two-year, $14 million extension with an option for 2015.