He was selected by the Chicago Bears with a seventh round pick in the 2010 NFL supplemental draft.

He played college football at Brigham Young where he became the school's second all-time leading rusher.

After the season-opener against the Arizona Wildcats in 2007, Unga earned the Mountain West Conference (MWC) offensive player of the week award.

Unga became the starting running back in 2007 due to an injury to Fui Vakapuna in the prior season.

As a starter, Harvey rushed for over 1,000 yards in just 11 games, with this mark reached in the second quarter against their in-state rivals, Utah, on November 24, 2007.

[4] On April 16, 2010, Unga voluntarily withdrew from BYU after violating its honor code.

[9] On August 31, 2011 the Bears received a roster exemption for Unga, who had left the team twice during the preseason for personal reasons.