Coleman was drafted 224th overall by the Tampa Bay Lightning in the 2003 NHL Entry Draft. Selected from the London Knights of the Ontario Hockey League, Coleman was awarded the Dave Pinkney Trophy on his way to capturing the Memorial Cup the following season in 2003–04. He is the first graduate of the NHLDiversity Program to be drafted and to play in the NHL, making his debut for the Lightning, in relief, on November 11, 2005. On February 24, 2007, Coleman was traded with a 1st round draft pick to the Anaheim Ducks for Shane O'Brien and a 3rd round draft pick. He was then assigned to the Ducks AHL affiliate, the Portland Pirates. Coleman attended the Chicago Wolvestraining camp for the 2008–09 season, before he was released. After starting the year in the ECHL with the Phoenix RoadRunners, Coleman was recalled to the Worcester Sharks but upon his return was traded to the Trenton Devils on November 21, 2008. Coleman was then credited as a major influence in the turn around Trenton Devils season going 27-8-2 for the remainder of the year. Coleman was then invited to the New Jersey Devils training camp for the 2009–10 before he was reassigned to AHL affiliate, the Lowell Devils. Coleman appeared in just three games with Lowell before he returned to Trenton for the season. After attending the St. Louis Blues training camp. Gerald Coleman played the 2010–11 season with the Alaska Aces posting a 2.19 GAA and a save percentage of.913, earning a record of 30-15-1-0 with 4 shutouts. In the Kelly Cup Playoffs, Coleman, along with the rest of the Aces set a playoff record with a 12-1 record to capture the cup. Coleman earned 11 of those 12 wins and did so with a.938 save percentage and a 1.73 GAA and 3 shutouts. In the end, Coleman lead the Alaska Aces win their second Brabham Cup and second Kelly Cup in franchise history. The Alaska Aces are also the only team to win the Brabham Cup and Kelly cup in the same year twice. He also captured goaltender of the year. He returned to the Aces the following season and after 23 games was signed to a professional try-out by the Lake Erie Monsters of the AHL. Coleman enjoyed a prominent role with the Monsters winning 11 of 17 games before returning to the Aces to finish a second consecutive year with the lowest goals against average in the ECHL. With off-season surgery and a forecasted lengthy recovery limiting interest from the AHL, Coleman re-signed with the Aces for his third season with the club on July 12, 2012. After his fourth season with the Aces, and backstopping the club to their second Kelly Cup Championship in his successful tenure, Coleman retired from professional hockey due to a persisting hip injuries on August 1, 2014. He intends to study in pursuit of a profession in physical therapy.
