Bicester-born Sam was captain of United’s successful under-18 side. He was awarded a professional contract upon completion of his scholarship at the end of the 2012/13 season, making him the club's current longest-serving player. Sam signed a new contract in May 2014 and another in June 2015.

Sam scored his first goal for the club against Southend on 17^th January 2015. Although nominally a centre back, Sam has also played successfully at both left back and right back. He signed another one-year contract in March 2017.