Coach Zaun joined the U14 Red Bulls in the middle of the 2010 season and helped guide the U14 Red Bull Pre-Academy to the Northeast Regional League Championship after defeating the other top three teams in a round-robin playoff by a combined 15-2 scoring margin. The following 2010/11 season the U14 Red Bulls team, which consisted of players born in 1996, finished with a 37-1-2 record and won the Northeast Regional League regular season and playoff championships. The U14 Red Bulls completed their strong season by winning the Generation adidas MLS Cup tournament after defeating Chivas USA in the championship game. During that season the team had 13 players invited to U14 and U15 US National Team camps. The team has also had a record seven players invited to join the U17 US National Team residency program in Bradenton, Florida.
In 2011/12 the U14 team finished with a 36-2-2 record and again won the Northeast Regional League and playoff championships. The team also played in the first ever NPL National Championship playoffs finishing second after losing to FC Dallas 1-0 in overtime in the final. The team was also invited to compete in the English Premier League Academy tournament. They defeated Chelsea, Newcastle, Palmeiras and Aston Villa before losing in the semi-finals to Ajax. During the season the team had six players invited to participate in U15 US National Team camps.
Prior to joining the Red Bulls, Zaun served as the Associate Head Coach at Rutgers University for eight seasons and during that time also worked as a Youth National Team Scout for US Soccer. During his time at Rutgers the team reached the NCAA tournament three times and the Big East playoffs six times. Zaun, who played at Rutgers from 1989 to 1992, was a four year starter and played in the NCAA tournament all four years. Two of those teams advanced to the Final Four, losing in the semifinal to Virginia in 1989 and in the championship game in 1990 to UCLA in penalty kicks. He earned Atlantic-10 Freshman of the Year honors in 1989, and captained the 1991 and 1992 squads and was a preseason National Player of the Year candidate in 1992. Zaun was inducted into the Rutgers Athletic Hall of Fame in 2008.
Upon his graduation from Rutgers in 1993, Zaun played for the North Jersey Imperials of the USISL. Zaun was then drafted in the fourth round of the inaugural Major League Soccer draft by theN.Y./N.J. Metrostars where he spent three seasons as a defender. He then moved on to the Chicago Fire for one season, before spending one season competing in the A-League with Lehigh Valley. He served as player/assistant coach for Lehigh Valley in 1999 prior to moving on to Rutgers. Zaun currently holds a USSF B coaching license.