He was drafted by the Washington Capitals in the fourth round, 112th overall, of the 2010 NHL Entry Draft. Grubauer has played with the German national team in several international tournaments, including the 2008 U18 World Championships and the 2009 World Junior Championships. Grubauer won the Memorial Cup with the Ontario Hockey League (OHL)'s Windsor Spitfires in 2010. Grubauer won the Stanley Cup as a member of the Capitals in 2018.