At the time of Tarley's selection for the Liberian U-21 national team in 1998, he was the youngest player in team history, only 14 years old. He played his first game for the senior national team in 2004. Tarley's first stint in Major League Soccer came with Real Salt Lake in 2005. The Colorado Rapids acquired Tarley’s rights from Real Salt Lake in exchange for a 4th round pick in the 2007 MLS Supplemental Draft on August 15, 2006. Tarley was waived by the Rapids at the end of the 2006 season and returned to the Minnesota Thunder of the USL-1 for one season, prior to joining the Puerto Rico Islanders in 2007.