O'Brien, 24, has registered two points (one goal, one assist) and 28 penalty minutes in 17 career games with the Capitals. The 6'1", 215-pound forward made his NHL debut on Oct. 9, 2014 against Montreal, earned his first NHL point with an assist on Oct. 14, 2014 against San Jose and scored his first career NHL goal on Oct. 26, 2014 at Vancouver.
In 74 games with Hershey last season, the Halifax, Nova Scotia, native recorded 28 points (15g, 13a), ranked fifth on the team in goals and second in penalty minutes (118).
In the 2017-18 season, O'Brien recorded 26 points (17g, 9a) in 69 games, setting a single season AHL high in goals, and ranked third on the team in penalty minutes (79).
O'Brien has earned 108 points (53g, 55a) and 555 penalty minutes in 311 career AHL games with Hershey.
O'Brien signed with Washington as a free agent on Oct. 6, 2014.
