The trade was made Saturday.
The 24-year-old McNeill has 5 goals, 1 assist and 36 penalty minutes in 18 games with the American Hockey League’s Texas Stars this season. He has played in 312 American Hockey League games since the 2011-12 season.
McNeill has played in two NHL games — one with Chicago in 2015-16 and one with Dallas in 2016-17.
The 25-year-old O’Brien has 3 points and 27 penalty minutes in 21 games for the AHL’s Milwaukee Admirals this season. He has appeared in 188 career AHL regular-season games.