When he was called up by Mariners in 1984, the 6’8″ Guetterman became the third-tallest player in major league history. Showing a pattern of near-invincibility in the beginning of the season but inconsistency the rest of the time, the reliever won his first five games for the Mariners in 1987 and was 8-1 at the All-Star break, but finished 11-4 with a 3.81 ERA.
After the season, Guetterman was shipped to the Yankees as part of a five-player deal that brought Steve Trout and Henry Cotto to the Bronx, and his five seasons in New York proved to be his most productive. In 1989 he set the Yankee record for scoreless innings from the start of a season with 29, but was hit hard for much of June and July before regaining his touch.
Guetterman got off to a bad start in 1992 and in June was dealt to the lowly Mets for Tim Burke, a right-handed reliever who, like Guetterman, was a born-again Christian. After finishing the year in Queens, Guetterman spent 1993 with St. Louis and ended his career with two unproductive seasons in Seattle.