The 24-year-old rearguard appeared in 17 regular-season games for the Boston Bruins last year, amassing one assist and compiling a minus-4 differential. He went on to suit up for five playoff games and picked up an assist.
Morrow also played three games with the AHL's Providence Bruins this past season.
A native of Edmonton, Morrow was a first-round pick of the Pittsburgh Penguins - 23rd overall - back in 2011. He boasts 65 games of NHL experience, all with Boston.
The six-foot, 199-pound blue-liner has two career goals and seven assists for nine points since making his NHL debut in 2014-15.
