Leven's first professional stint came after signing with the
Perth Wildcats of the Australian
National Basketball League in 2006. For the second half of the 2006–07 season, he played for
Oberelchingen in the German
ProB. In nine games, he averaged 28 points per game. Leven began the 2007–08 season practicing with Spanish team
Unicaja. On 25 January 2008, he joined Icelandic team
Snæfell. In 17 games, he averaged 16.2 points, 2.0 rebounds, 1.4 assists and 1.1 steals per game. Leven initially signed with Greek club
Kavala/Panorama for the 2008–09 season, but never debuted for them and left due to their financial problems. He later joined Dutch team
West-Brabant Giants in March 2009. In 16 games to finish the season, he averaged 7.9 points, 1.2 rebounds and 1.1 assists per game. In the 2009–10 season, Leven played for the
Tees Valley Mohawks of the English Basketball League (EBL). In 15 games, he averaged 23.4 points, 4.4 rebounds, 3.5 assists and 2.3 steals per game. Leven initially signed with Greek club
SEFA Arkadikos for the 2010–11 season, but never debuted for them and left due to their financial problems. ==National team career==