[2][3] He was also a member of the two-time National Champion Michigan Wolverines men's gymnastics team.

[4] Sebastian was born in Belfast, Northern Ireland to parents Anthony and Veronique, both physicians educated in India.

[5][6] He grew up in Oklahoma City, Oklahoma where he attended Bart Conner Gymnastics Academy training under World Champion and Olympic gymnast Ivan Ivankov.

[7][8] Holding dual U.S. and Irish citizenship, he first represented Ireland at the 2008 European Championships in Lausanne, Switzerland.

As a freshman in 2010, he earned Michigan's first ever Big Ten Freshman of the Week award and helped lead Michigan to an NCAA Division 1 team championship as the lead off gymnast in the final rotation.