One game into his major league career, Cam Schlittler is the hardest-throwing member of the New York Yankees’ rotation. Schlittler used his 100 mph fastball to shut down Cal Raleigh and the Seattle Mariners during an eye-opening debut Wednesday night, pitching the Yankees to a 9-6 victory before a throng of friends and family members in the crowd. One of the team’s top-rated prospects, the 6-foot-6 Schlittler struck out seven over 5 1/3 innings to earn the win. He threw New York’s seven fastest pitches this season and his average fastball velocity of 97.9 mph was the highest for a Yankees pitcher this year. But it was his poise and improved secondary pitches that really impressed manager Aaron Boone.