Having grown up in a family of renowned skaters, with both his grandparents and parents being skaters, Theslof was exposed to sports being a viable career option from a very early age. While his younger brother Tyler initially chose to become an ice hockeygoaltender, Nick was interested in soccer and began playing for the youth indoor soccer club, the Cleveland Crunch. In 1991, his coach at the club, former English striker Ron Wigg, advised then PSV Eindhoven head of youth developmentHuub Stevens to have a look at Theslof, during a match for which PSV's reserve team had come to Cleveland. Stevens, impressed with Theslof's potential, offered him a youth contract at PSV, which Theslof accepted and moved from his home in Columbus to Eindhoven, the Netherlands. He subsequently played for PSV for the next two years, before his career abruptly ended due to an Achilles injury. He later moved back to the United States and attended UCLA, where he later played for their soccer team, where his performances were lauded. On February 1, 1998, the Columbus Crew selected Theslof in the 1998 MLS College Draft, but he was released during the 1998 season without playing a first team game. He moved to the Orange County Waves for the 2000 USL A-League season. In 2005 and 2006, Thesloff inserted himself into several Blue Star games.
Coaching career
Theslof began his coaching career as Dr. Jay Martin's assistant at Ohio Wesleyan University between 1998 and 2000, winning the NCAA Division III national title in 1998. Following his stay at Ohio Wesleyan, Theslof became head coach of the Orange County Blue Star, a team of the AmericanPremier Development League and spent time with Juergen Klinsmann who enjoyed Amateur Soccer in Southern California. During that time he also coached future American national team players Sacha Kljestan and Sal Zizzo. In 2004, Theslof coached his old club PSV's youth squad in the Netherlands. After Klinsmann became manager of the German national team, he appointed Theslof as coach and scout in 2006 during the 2006 FIFA World Cup, where he wrote detailed match summaries and reports for Klinsmann. In February 2008, after he was appointed manager of FC Bayern Munich, Klinsmann appointed Theslof as a second assistant coach and scout. On April 27, 2009 Klinsmann and his two assistant coaches were released early, even though they had won five of the previous seven league games and were only three points behind league leader VfL Wolfsburg.
