For a brief period in the mid-80s, Phelps was one of the more dangerous hitters in the American League, hitting 108 home runs in the span of 524 games. And while his high strikeout totals and low batting averages offset his power stroke, he compensated with an equally high walk total and high on-base percentage, exceeding .400 in three straight years. Though Phelps was something of a defensive liability, playing just 115 games in the field in his eleven-year career, he became a respected pinch-hitter and designated hitter when he wasn’t platooning at first.
In two call-ups with the Kansas City Royals in 1980 and ’81, Phelps disappointed the front office with 15 strikeouts in 26 at-bats, prompting a trade to the Montreal Expos. A remarkable 46 homers and 141 RBIs in Double-A the following year prompted a late season promotion north of the border, where he was utilized solely as a pinch-hitter, notching two hits in eight at-bats.
Montreal sold the promising Phelps to his hometown Seattle Mariners in the offseason, and in 1983 the blossoming slugger hit .341 in the Pacific Coast League, inducing a mid-season call-up during which he connected for seven homers. Though he was supposed to win the first base job the following season, he broke his finger in the first week of April, and prospect Alvin Davis stepped in to win the job. Phelps ended up in a part-time role as DH, pinch-hitter, and backup first baseman, yet still slugged 24 round trippers in just 290 at-bats.
Despite developing a power stroke at the plate, Phelps was a very selective batter and would often lay off a ball even slightly out of his range. This amounted to a number of called punchouts, and 73 strikeouts altogether in 1984, somewhat minimizing the effect of his homers. But if his selectivity hampered some of his run production, it also helped his on-base percentage — he walked once in every 4.8 plate appearances from 1984-85, and even tallied 80 walks to 75 strikeouts in 1987, when he notched a .410 OBP.
Phelps’ power was well-suited to the hitter-happy Kingdome, but when he ironically began to receive publicity about being underpublicized, the Mariners shipped him to the power-hungry New York Yankees for Jay Buhner in July 1988, a deal the Bombers would come to regret. Used as a part-time designated hitter and pinch-hitting power threat with the Yanks, Phelps initially contributed to the run effort, finishing up 1988 as the leader in the AL for home run percentage, going yard once every 12.38 at-bats.
The next year, however, Phelps hit just seven homers in pinstripes before being dealt to the Oakland Athletics in August 1989 for pitcher Scott Holcom. In June 1990, the A’s sold him to the Cleveland Indians, where he finished his career ignobly, going 7-for-61 to close out the season.