Selected by the Boston Bruins in the fourth round (No. 121) of the 2011 NHL Draft, Ferlin drew notice in junior hockey by scoring 25 goals and 73 points during the 2010-11 season for Indiana of the United States Hockey League. Bruins scouts liked Ferlin's size (6-foot-2, 217 pounds), his ability to play along the boards and in traffic and his toughness in front of the opponent's net.
Having already committed to Cornell University, after being drafted Ferlin joined the Big Red for the 2011-12 season. He had eight goals and 21 points and was named both the ECAC and Ivy League's top rookie.