CARLTON'S NAB Cup exit in Blacktown on Saturday night has been compounded by the news that forward Brad Fisher has torn his anterior cruciate ligament.

Fisher had been expected to play a bigger role in Carlton's forward line this year, given the absence of Coleman Medallist Brendan Fevola. He was limited to seven senior games in 2009 and finished the season in the VFL.

The 25-year-old underwent a knee reconstruction after rupturing his ACL in 2004, and coach Brett Ratten confirmed after the match that the injury was to the same knee.

"For a player who worked so hard through the pre-season, to only get to round one of the NAB Cup, it's not great news," Ratten said.

Fisher has played 98 games for the Blues since debuting in 2003.