He was originally a third baseman and catcher in his first two professional seasons; however, in 1969, he also pitched (although in 1970 he spent a few games at second base).
Save for the years he managed, he was a Pitching Coordinator in the lower minors in the Astros' system from 1982 through 1984.
During that time period he was also the Houston Astros Minor League Spring Training Coordinator.
From 2000 to 2005, he served as their administrative coach, which included coordinating Major League Spring Training and administering the defense and pitching charts as well as video and advance scouting reports.
In February 2014, Alfonso became Coordinator of International Development and Special Assignment Scout of the Houston Astros.