Green became a full-time referee at the start of the 2005 NFL season after Grier was forced to retire due to a leg injury. Green's first experience as an NFL referee came on October 3, 2004 during a game between the New England Patriots and the Buffalo Bills. Green's 2013 NFL officiating crew consisted of umpire Bruce Stritesky, head linesman Tom Stabile, line judge Mike Spanier, field judge Boris Cheek, side judge Larry Rose, and back judge Scott Helverson. During a game he was officiating between the Pittsburgh Steelers and San Diego Chargers in 2008 Green ruled a lateral play by the Steelers as illegal, a decision he later conceded was wrong. The incident has prompted the NFL to discuss "potential administrative improvements for replay that would help to prevent this type of mistake in the future."