O'Brien, a centreman for the Prince George Cougars, is considered a prospect for the 2016 NHL draft, which will be held in Buffalo in June. He put himself on the radar of NHL scouts while playing with the junior A Prince George Spruce Kings last season and moved up to the Western Hockey League level with the Cougars this season.
As a first-year member of the Cats, O'Brien established himself as one of the team's top offensive threats. He finished the regular season with 18 goals and 56 points, a total that placed him fifth on the club. Within the WHL, O'Brien finished fourth in the rookie scoring race.