Career
Kirk, a 7"0" center, played at Los Alamos High School in Los Alamos, New Mexico. He came to the University of New Mexico in 2010, averaging 4.7 points and 3.7 rebounds per game in the 2010-2011 season. In the offseason, Kirk underwent back surgery for a herniated disc and subsequently redshirted the 2011-2012 season.
Kirk bounced back as a redshirt sophomore, averaging 12.1 points, 8.1 rebounds and 1.8 blocked shots per game.
In the summer of 2013, Kirk was named to the United States" team for the 2013 Summer Universiade. He averaged 3.7 points and 4.6 rebounds as the team finished in ninth place.
In 2013-2014, Kirk increased his numbers to 13.2 points, 8.7 rebounds and 2.7 blocks per game. In April 2014, Kirk declared for the National Basketball Association draft, foregoing his final year of college eligibility.
Cleveland Cavaliers
After going undrafted in the 2014 National Basketball Association draft, Kirk joined the Cleveland Cavaliers for the 2014 National Basketball Association Summer League.
On August 11, 2014, he signed with the Cavaliers. During his rookie season with the Cavaliers, he had multiple assignments with the Canton Charge of the National Basketball Association Development League. On January 5, 2015, Kirk was traded to the New York Knicks in a three-team trade that also involved the Oklahoma City Thunder.
Two days later, he was waived by the Knicks.
Canton Charge
On January 10, 2015, Kirk was acquired by the Canton Charge. In 46 games for the Charge in 2014-2015, he averaged 12.5 points, 6.5 rebounds, 1.1 assists and 1.1 blocks per game.
Pistoia Basket 2000
On August 15, 2015, Kirk signed with Pistoia Basket 2000 of the Italian Serie A for the 2015-2016 season.