In 2006 and 2007 Wassermann was a volunteer assistant for the men's soccer team at Saginaw Valley State. In 2006, he also served as the head coach of the junior varsity boys' soccer team at Saginaw Heritage High School. In 2007, he was head trainer and coach for Saginaw area youth teams.
From 2010 through 2014, Wassermann was head coach at his alma mater, Saginaw Valley State. Taking over a program without a winning tradition, he quickly turned SVSU into a national power in Division II, advancing to the national championship game in only his third season. In his five-year tenure at SVSU, his Cardinals teams won two GLIAC season championships, two GLIAC tournament championships, and advanced to the NCAA tournament in 2011, 2012, and 2014. Wassermann received GLIAC Coach of the Year honors in 2011 and 2012. After the 2012 Cardinals advanced to the Division II College Cup championship game. Wassweman was named both the Midwest Region Coach of the Year and the Division II National Coach of the Year by the National Soccer Coaches Association of America (NSCAA) (now known as the United Soccer Coaches).
From 2014 through 2018, Wassermann was assistant coach and recruiting coordinator for the Michigan State Spartans. With Wassermann on staff, the Spartans were in the NCAA tournament in 2016, 2017, and 2018.. The 2018 squad reached the NCAA College Cup before being beaten by Akron in the national semifinals. The 2018 squad advanced to the quarterfinals, and the 2016 team was upset on penalty kicks in the NCAA first round by SIUE. At Michigan State, Wassermann coached two All-America selections, 13 All-Region picks, and 17 All-Big Ten performers, including the 2016 Big Ten Freshman of the Year, 2017 Goalkeeper of the Year, and 2018 Midfielder of the Year.
On January 17, 2019, Wassermann was announced as the new head coach of the SIUE Cougars. He told the St. Louis Post-Dispatch that, of the 11 available Division I head coaching positions, SIUE was the only school that was desirable enough for him to apply. He also said that he had been aware of the program since playing against the Cougars as a midfielder at SVSU.
Wassermann has also previously served as the head coach for the Under-18 USA Youth team for Maccabi USA and as the associate head coach for Detroit City FC of the National Premier Soccer League (NPSL).
National champion
Postseason invitational champion
Conference regular season champion
Conference regular season and conference tournament champion
Division regular season champion
Division regular season and conference tournament champion
Conference tournament champion