Warsofsky had his most productive NHL season in 2017-18, the defenseman's first with the Colorado Avalanche.
Warsofsky went from Cushing Academy in his native Massachusetts to USA Hockey's National Team Development Program in 2007-08 and was named captain. He was captain of the U.S. team that won the bronze medal at the 2008 IIHF World Under-18 Championship. Months later the St. Louis Blues selected him in the fourth round (No. 95) of the 2008 NHL Draft.