human rain delay (1980)

“People always thought [Bob] Walk was a human rain delay, but compared to [Juan] Eichelberger, Walk works like Jim Kaat.” Jayson Stark, “Padres Snap Phils’ Streak with 4-3 Win,” Philadelphia Inquirer, June 20, 1980, p3-C

Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
No first use cited, but notes that the term was applied to Mike Hargrove and Carlton Fisk. The name was most commonly applied to Hargrove, but the above citation appeared two months before the earliest known use of the term for him.