Based on his improved condition and a successful spring training, the Mariners indicated that in 2007 they would no longer limit the number of innings Hernández could pitch, focusing instead on pitch counts to avoid overuse. Hernández won the honor of being named the team's Opening Day starter. He became the youngest pitcher chosen for this assignment since Dwight Gooden in 1985. He pitched eight innings of a 4–0 victory over the Oakland A's, allowing three hits and two walks while setting a career high with 12 strikeouts.