He is one of only two players to hit a home run in his first and last major league at-bats. The other is Paul Gillespie. Miller's first and last major league at-bat home runs (off Lee Stange and Jim Merritt respectively) were the only two home runs he hit in his MLB career.
Following his major league career, Miller played for three seasons in Japan, from 1970 until 1972 for the Chunichi Dragons. There, he primarily played first base, batting .245 with 79 home runs over those three seasons.