[2][3] Seminick was born in Pierce, West Virginia to Lemko immigrant parents,[4][5] but moved to Muse, Pennsylvania when Andy was two.

[2][9] On June 2, 1949, the Phillies hit five home runs during the eighth inning in a 12–3 victory over Cincinnati at Shibe Park, tying the major league mark set by the 1939 New York Giants.

With his defensive and pitch calling skills improved, Seminick played an important leadership role during the 1950 "Whiz Kids" championship season.

[2][3] Because he was, at 29, one of the veterans on the squad and was called upon to handle a young Phillie pitching staff, Philadelphia baseball writers nicknamed Seminick "Grandpa Whiz.

A nearly ten-minute brawl erupted between the teams, which required police intervention and resulted in the ejection of Seminick and Rigney from the game.

Seminick broke his ankle late in the season, but continued to play with the injury until the Phillies lost to the New York Yankees in the World Series.

[4][14] Future Hall of Fame pitcher, Robin Roberts said of Seminick,"If you had to pick a guy in the clubhouse who was our leader that year, it would be Andy.

Notably, ninety of the players he managed or coached eventually played in the major leagues, including Mike Schmidt, Ferguson Jenkins, Greg Luzinski and Bob Boone.