After graduating from high school in Northbridge, Massachusetts, Vandersea played football for the University of Massachusetts Amherst, weighing in at 245 pounds and standing 6'3" tall.

Vandersea played linebacker and defensive end.

He was drafted by the Green Bay Packers in the 16th round (220th overall) of the 1965 NFL draft and played for the 1965 NFL Champion Packers in 1966, and also the 1968 and 1969 seasons.

While playing for the Packers, Phil wore jersey number 37.

This biographical article relating to an American football linebacker born in the 1940s is a stub.