His AFL career began in 1996 when he debuted for the Essendon Bombers. He was one of Essendon's consistent players in the years 1999, 2000, 2001 and 2002. Blumfield was a member of the Essendon 2000 premiership team, which defeated Melbourne in the 2000 AFL Grand Final and won a record 24 out of 25 games for the season.
At the end of 2002, he was traded to the Richmond Tigers to help Essendon meet the total player payments limit.[1] He played 19 games over two seasons before he was delisted by them at the end of season 2004. Blumfield returned to be a playing assistant coach for Essendon's affiliated club in the Victorian Football League, the Bendigo Bombers.[2] He was made a life member of Essendon on 15 December 2010.