At age seventeen, Valle was selected by the Seattle Mariners in the second round of the 1978 MLB draft. He played in the minor leagues for seven seasons before making his MLB debut at age 23 with the Mariners in 1984 on September 7. For the next two seasons, he split his playing time with the Mariners and the Calgary Cannons of the Pacific Coast League, producing a .312 batting average with 21 home runs and 71 runs batted in with Calgary during the season.
