Butler made his debut for the West Coast Eagles in Round 10, 2004 against Richmond, gathering 14 disposals, 5 marks and 1 goal in a 37 point win to the Eagles. He went on to play 12 games that season, including a losing elimination final against Sydney.
In 2005, he played 14 games for the club including the losing grand final against Sydney.
2006 was a much more successful seasons for Sam. He played his first game of the season in round 13 against the Western Bulldogs, picking up 22 disposals and 6 marks. He notched up a further 13 games (14 games in total for the season) and having a superb 2006 final series, in particular his performances against the Western Bulldogs in the semi final (30 disposal, 3 marks, 6 tackles) Adelaide in the preliminary final (22 disposals, 6 marks, 1 goal), as well as being part of the 2006 premiership winning team over Sydney.
In 2007, he struggled with a persistent groin injury (osteitis pubis) and was restricted in the games he played, not playing any AFL games and only playing a handful of WAFL and WAFL reserve games for Perth.
He has had a slow start to season 2008, having a modified pre-season training program due to his nagging groin injuries and played 5 games for his WAFL side Perth, playing 2 reserves games and 3 senior games. He was given a week off before making his return to the Eagles senior side against Sydney in Round 11.