The
Tampa Bay Buccaneers selected Hammel in the 12th round (307th overall) of the
1990 NFL draft. On December 5, 1990, Hammel was signed to the
Atlanta Falcons practice squad, but was released on December 12. In 1991, he played for the
New York/New Jersey Knights in the
World League of American Football (WLAF). Hammel started the first game in Knights franchise history against the
Barcelona Dragons, but was replaced in the first half by
Jeff Graham. In 1992, Hammel played for the Dallas Texans of the
Arena Football League (AFL). In his first season with the Texans, Hammel threw for 28 touchdowns on 157 of 308 attempts for 1,799 yards. Hammel led the Texans to a playoff victory over the
Albany Firebirds where he threw four touchdown passes. In 1993, Hammel returned and threw for 39 touchdowns and 2,287 yards. In 1994, Hammel signed with the expansion franchise
Fort Worth Cavalry of the (AFL). General Manager and head coach
Michael Trigg was Hammel's
offensive coordinator the two years he spent in Dallas. Hammel split playing time with fellow quarterback
Kyle Mackey. On the season, Hammel tossed 28 touchdowns while passing for 1,745 yards. In 1995, Hammel signed with the
Milwaukee Mustangs of the (AFL). Hammel followed Trigg's to Milwaukee where he played for the Mustangs for five seasons. In 1998, he threw for a career high 60 touchdowns and 3,100 yards. In 1999, he became the first player in Arena Football League history to pass for 18,000 yards, 300 touchdowns and 1,500 completions. In 2000, Hammel signed with the
Florida Bobcats of the (AFL). He appeared in three games for the Bobcats. In 2001, Hammel signed with the
Houston Thunderbears of the (AFL), who were a traveling team for the season. In 2002, Hammel signed with the
Grand Rapids Rampage midway through the season where he appeared in two games. In week 12 against the
Chicago Rush, he relieved starting quarterback
Clint Dolezel and led the Rampage to 20 straight points in a near come from behind victory. In 2003, Hammel signed with the
Las Vegas Gladiators of the (AFL). In 2004, Hammel signed with the
Philadelphia Soul of the (AFL). In 2005, Hammel signed with the
Chicago Rush of the (AFL). In his first start of the season against the
Nashville Cats he threw for 223 yards and five touchdowns in a 45–38 victory, filling in for injured starting quarterback
Raymond Philyaw. The following week, he won his next start throwing six touchdowns on 21 of 25 completions against the
Grand Rapids Rampage. In 2006, Hammel signed with the
Colorado Crush of the (AFL). On May 28, 2009, Hammel signed with the
Milwaukee Iron of the
AF2. At 42 years of age, Hammel returned to professional football after not playing the previous two seasons. He was the oldest player in the league. In the season finale, Hammel completed 24 of 35 passes for 317 yards and seven touchdowns against the
Albany Firebirds. In July 2010, Hammel signed with the
Jacksonville Sharks of the (AFL). Following an injury to Sharks' starting quarterback
Aaron Garcia, Hammell was signed to backup
Bernard Morris. He never appeared in a game for the Sharks. On August 7, 2010, Hammel signed with the Chicago Rush of the (AFL). Hammel was signed as a backup quarterback for the playoffs. The Rush had been without a backup since starting quarterback
Russ Michna went down with an injury. For the playoffs, he did not appear in a game while backing up
J. J. Raterink. On July 7, 2011, Hammel signed with the
Utah Blaze of the (AFL). The Blaze would be Hammel's 13th and final indoor football team. Hammel started and played the final three games of the season. In game 17 against the
New Orleans Voodoo, Hammel found wide receiver
Chris Bocage on a game winning touchdown pass in the final seconds. In the season finale against the
Cleveland Gladiators, he threw seven touchdowns while completing 31-of-44 passes for 355 yards in a 76–69 victory. ==Career statistics==