After his senior year of college Garrison was automatically eligible for the
2006 NBA draft but he was not selected by an NBA franchise. The
Los Angeles D-Fenders drafted Garrison in the
2006 NBA Development League draft with the 42nd overall pick. Garrison was also drafted in the 2006 Continental Basketball Association draft with the 25th overall pick by the
Atlanta Krunk Wolverines: since the Wolverines ultimately did not take part in the CBA season, Garrison signed for the
Great Falls Explorers as a free agent. He played 41 games, started 10, and in 24.4 minutes per game he averaged 11.9 points, 6.1 rebounds, 0.6 assists and 0.9 blocks on 51.7% shooting (80.5% from the free throw line), winning the CBA Rookie of the Year award. His successful stint in the CBA earned him an opportunity to play in the
Korean Basketball League with the
Seoul SK Knights; he then played in
Spain,
Venezuela and
Argentina to end the season. In 2008 he transferred to
Turkey, and he signed for
Pamukkale Üniversitesi where he played in the Turkish second division. At Pamukkale he played the final part of the 2008–2009 season, during which he averaged 20.4 points and 9.4 rebounds, and the first part of the 2009–2010 season where he recorded 21.1 points and 10.2 rebounds. He then signed for
Ukrainian team Khimik where he played 2 seasons from 2009 to 2011, averaging 9.5 points in his first year and 8.3 in his second year. He moved again to Turkey in 2011, this time joining Mailye Milli Piyango. In 2011 he signed for Greek team Kavala where in 11 games he averaged 5.3 points and 2.5 rebounds; he had better stats at Ilisiakos where he played 9 games of the 2012–2013 season, averaging 5.8 points and 5.8 rebounds. He was drafted in the
2013 NBA Development League draft with the 5th pick of the 5th round by the
Texas Legends but he did not play in the D-League: he then moved to
Lithuania where he played for the second-level team Palanga. In 2015 he moved to
Bahrein and then to Mexican club
Ostioneros de Guaymas of the
CIBACOPA, averaging 5.0 points and 2.8 rebounds. In May 2017 he signed for
Paraguayan team Sol de América. ==References==