Ashton Agar has been suspended from Western Australia's next Sheffield Shield match after being reported for showing dissent at an umpire's decision during the Futures League earlier this week.

Cricket Australia has been cracking down on Code of Behaviour breaches this summer and because it was Agar's second offence in 18 months - he was fined for another show of dissent in as Shield game in November - the charge was upgraded and Agar was suspended.

Agar admitted to the offence, which occurred during the Futures League game between Queensland and Western Australia at Allan Border Field in Brisbane this week.

The suspension means Agar will be unavailable for Western Australia's home Shield match against Tasmania starting on February 12. Agar has played all six possible Shield games this season for 14 wickets at 47.85.