2009-10: Jack Downing skated in 36 of 39 games for the University of Vermont. He was tied with fellow junior Justin Milo for fourth in scoring for the Catamounts with 21 points. He scored 4 of his 9 goals on the power play and had 12 assists with 16 penalty minutes. Despite finishing eighth in Hockey East during the regular season, Vermont reached the Hockey East semifinal against eventual national champion Boston College and earned an at-large bid to the NCAA West Regional.
2010-11: In what was a disappointing season for the Catamounts team-wise, Downing led the club with 13 goals and had 5 assists; skating in all 36 games. His 49 penalty minutes were tops on a team that won just eight games and finished last in Hockey East.
2011-12: Signed to a free agent contract by Ottawa's AHL affiliate Binghamton in August 2011, Downing played in 47 AHL games and also skated for the ECHL's Elmira Jackals in his first pro season. He scored 9 goals with 8 assists and was an even plus/minus with 27 penalty minutes. Downing scored 11 goals with 8 assists in 25 games for Elmira and was minus-five with 13 penalty minutes. Elmira reached the second round of the playoffs after finishing first in the Atlantic Division. Skating in 4 of 10 playoff games, Downing had 1 assist and 2 penalty minutes.
Was sent to the Elmira Jackals of the ECHL to play in the 2012-13 season, but may see more action with Binghamton in the AHL.