Hamblin joined the Harvard University women's soccer staff in 2011. Previously he served as an assistant coach with the Boston Breakers in 2010, was an associate head coach at Boston College from 2001-2009. At BC, Hamblin helped the Eagles reach the NCAA tournament seven times and advance to the Sweet 16 on four separate occasions.

Hamblin has also been involved with US Youth Soccer ODP Region I, serving as a staff coach from 2003-2011. In March 2008, Hamblin coached the Region I U-17 team in Russia, as it advanced to the tournament final, where it came up just short — losing on penalty kicks to the U-17 Chinese National Team. Hamblin has served as a U.S. Soccer National Training Center Staff Coach since 2013, and in 2010 was named Massachusetts Youth Soccer's Girl's Competitive Coach of the Year. 

As a player, Hamblin helped the Boston College men's soccer team to the Big East Championship in 2000 and its first NCAA bid since 1990. Hamblin was selected as Big East Goalkeeper of the Year and an NSCAA First-Team All American. In 2001, Hamblin was selected as the Big East's Male Scholar-Athlete of the Year and Boston College honored him with the 2001 Outstanding Male Student-Athlete Award. Hamblin had a brief professional career, playing for Steve Nicol and the Boston Bulldogs during the summer of 2001.