A hulking defenceman, Green went on to play one season with Green Bay of the USHL before enrolling at the University of North Dakota in the fall of 2002. Over the course of the next three years, the Grand Ledge, MI native was a workhorse on the blue line and opted to forego his senior year and turn pro.

In 2005-06, Green spent the better part of the season with the AHL's Iowa Stars however, made his playoff and Oiler debut in the 2006 playoffs competing in 17 of 18 games. He suited up for each game in the Stanley Cup Final in 2006, however the club and Greene would finish one win shy of their ultimate goal.

After a steady sophomore season in Edmonton, Greene was limited to 46 games throughout the 2007-08 season due to a ankle injury. In the summer of 2008, Greene was sent to the Los Angeles Kings via a three-player trade.

In Los Angeles, Greene would assert himself as one of the league's premier defensive defenders. In 2011-12 he was a key part of the Los Angeles Kings club that stormed through the Western Conference playoffs and defeated the New Jersey Devils to capture the first Stanley Cup in franchise history. Greene's consistent play injected a necessary stability to the Kings' back end.

During the 2013-14 season, the Kings once again made it to the Stanley Cup Final where they would defeat the New York Rangers in five games. The win gave Greene and the Kings their second Stanley Cup in three years.

Injuries would plague Greene during the 2015-16 and 2016-17 seasons, limiting the defender to just 29 games in two years. On August 14, 2017, he officially announced his retirement from the game and joined the Kings front office staff.