Cleveland Cavaliers After going undrafted in the
2014 NBA draft, Kirk joined the
Cleveland Cavaliers for the
2014 NBA 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
NBA 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 2014–15, 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 2015–16 season. Kirk averaged 16.3 points and 7.6 rebounds per game for Pistoia, which reached the
Serie A playoffs before being eliminated in the first round by
Scandone Avellino.
Guangzhou Long-Lions In July 2016, Kirk played for the
San Antonio Spurs in the Utah session of the
2016 NBA Summer League. He then played for the
Toronto Raptors in the Las Vegas session. On July 29, 2016, Kirk signed to play for the
Guangzhou Long-Lions of the
Chinese Basketball Association for the 2016–17 season. On November 15, he was released by Guangzhou.
Anadolu Efes On January 16, 2017, Kirk signed with Turkish club
Anadolu Efes for the rest of the season.
Alvark Tokyo On July 26, 2017, Kirk signed with
Alvark Tokyo of the Japan
B League. Alvark Tokyo won the 2017–18 B League championship, and Kirk led the team, averaging 16.2 points and 8.8 rebounds per game for the season. In the summer of 2017, Kirk played in
The Basketball Tournament on
ESPN for
The Stickmen. He competed for the $2 million prize, and for The Stickmen, he averaged 6.5 points per game. Kirk helped take The Stickmen to the second round of the tournament, where they then lost to Team Challenge ALS 87–73. In TBT 2018, he played for Eberlein Drive. Eberlein Drive made it to the championship game, where they lost to Overseas Elite. ==NBA career statistics==