There's a case to be made for differentiating between a Ryan Howard - who sought to continue his career with other clubs, albeit unsuccessfully - and a Mike Schmidt, who stayed with the Phils until the end (and had the self-awareness to recognize when it was time...), and had no interest in trying to "catch on" with somebody else.
Without doing the research...are the four guys listed by BR the only Phillies who met the 10 season criterion, and never played in another MLB organization?
But no. Terry Harmon spent most of 1968 playing for the Buffalo Bisons - the AAA affiliate of the Washington Senators. I don't know the particulars of how he got there - or how he then returned to the Phils' Florida Instructional League team that autumn. Bob Miller appeared in six games in 1969 with Montreal - then the AAA affiliate of the Dodgers. So if Miller and Harmon belong on this list, then Howard does, as well.
