Meche debuted with the Mariners on July 6, , two months shy of his twenty-first birthday, making him the second-youngest debut for the Mariners at that time (only Ken Griffey, Jr. was younger). Pitching with a 2–1 lead over the Anaheim Angels and two outs in the sixth, Meche walked two consecutive batters to force in a run and surrender the lead. He ended up with a no-decision. His first win came on July 19 against the Arizona Diamondbacks. For the season, Meche went 8–4 with a 4.73 earned run average.