As an administrator, manager, and coach, John Armentrout has been associated with baseball for more than 33 consecutive years, holding volunteer leadership positions at the local league, District, State, and Regional levels.

He started in 1988 as a T-Ball manager with the Greater Manassas Baseball League, located in northern Virginia.  John climbed the baseball age-group ladder as a manager all the way through the Babe Ruth 16-18 Division.  Many of those seasons included serving as a tournament team manager.  Along the way, John managed in several other youth sports organizations, including the Prince William Basketball Association, American Legion Baseball, and Prince William County Fall Extended High School Baseball League.  In 2001, John established the current day Virginia Eagles Baseball Club, which initially offered opportunities to college athletes during the summer.  From 2001 through 2004, the Club played in the collegiate Summer Wood Bat Baseball "Industrial" League.  John remains as the President & General Manager of the Virginia Eagles Baseball Club.

John's administrative career began when he was elected to the Manassas Board and appointed to the position of T-Ball Commissioner in 1990.  By the end of 1996, John had held many positions in Manassas, including Vice President and President.

In October 1996, John was appointed Assistant District 8 Commissioner.  When the District 8 Commissioner, Don Rose, Sr., was elected Virginia State Commissioner in the fall of 2003, John was elected to replace Don as District 8 Commissioner.

John served as District 8 Commissioner until he was appointed to the newly established position of Assistant State Commissioner, Training & Compliance, in October 2004 (and elected to the following year).  In October 2011, Babe Ruth League Southeast Regional Commissioner Henry Sermons appointed him Assistant Commissioner, Operations, the position that he currently holds.

John has pioneered the use of Web-based technology in Babe Ruth League, starting at the local league level, then establishing the first Babe Ruth Leagues of Virginia website in 1999, and now being Webmaster for the Southeast Region and maintaining most of the State websites in the Region.  Downloadable manuals and forms, the Manager's Tournament Information Package, and on-line brackets featuring instant access to tournament score updates are a few of the many innovative time- and cost-saving online features that he has introduced.

In 2021 John was inducted into the Southeast Region Hall of Fame.