On September 10, 1986, Valdez made his major league debut against the
New York Mets giving up five earned runs and nine hits through six innings to record his first major league loss. In 1986, he started five games and lost four of them. He returned to the majors after leaving in 1989 as a reliever, starting just one in 19 appearances, and earning a 6.06 ERA with a 1-2 record. He was selected off
waivers from the Braves by the Indians on April 30, 1990. The Indians used him as a starter and reliever (13 of 24 appearances with the Indians were starts) and overall that year he went 6-6 with a 4.85 ERA. He had his best year in 1992, when he went 0-2 with a 2.41 ERA. His
WHIP was a microscopic 0.991. However, in 1993 he only pitched three innings. The Giants used Valdez as a starter once again, despite his having been used as a reliever throughout most of his career. He went 4-5 with a 4.75 ERA. ==References==