Tommy John was not a special hitter during his time with the Dodgers. Rick Rhoden, Charlie Hough, and Terry Forster were better. I looked him up. He was an okay hitting pitcher, exceeding .200 once with the Sox, and once with the Dodgers. He had two home runs in only 69 at bats early on with the Sox, so that might be what you were thinking of.
Was mainly thinking of the whole staff. The sox actually used gary peters to PH. Burgess was a genius as PH.