One of several Expos rookies in 1988 who had a losing record despite pitching well, Holman was traded to the Mariners with pitchers Randy Johnson and Gene Harris for Mark Langston in May 1989. Considered the best of the three, Holman immediately moved into the Mariners’ rotation.
Holman pitched well for Seattle, even coming within one out of a perfect game on April 20, 1990 when Ken Phelps dashed his hopes with a pinch-hit homer in the ninth. But after an eleven-win season in 1990 and a thirteen-win campaign the following year, Holman tore his rotator cuff. Despite his best efforts (including a rehabilitation regimen that included an underwater throwing exercise, complete with snorkel) Holman never pitched in the majors again.