Defenceman who began his NHL career with the Edmonton Oilers in 2012, making the NHL All-Rookie Team. He helped the Pittsburgh Penguins win Stanley Cup Championships in 2016 and 2017.
He played college hockey for the University of Wisconsin Badgers. Prior to his NHL debut, he was named American Hockey League Defenceman of the Year with the Oklahoma City Barons.
He won back-to-back WCHA Defensive Player of the Year awards in 2010-11 and 2011-12.
He has a brother named Brendan.
He has been teammates with Jordan Eberle in Edmonton.