Westhoff was offered a one-match suspension by the Match Review Panel for striking opponent Cale Hooker during the Power's 30-point loss to Essendon on Sunday.
The 26-year-old is not risking a longer suspension by challenging.
If found guilty, the penalty will remain at one match, ruling him out of Saturday's clash with Hawthorn at AAMI Stadium.
The MRP graded Westhoff's strike intentional, low impact and high contact, a two-week offence.
However, his good record reduces the penalty to one week.
The other three players cited by the MRP on Monday have accepted their sanctions, including Adelaide's Shaun McKernan (two weeks for striking Eagle Brad Sheppard), Greater Western Sydney's Taylor Adams (one match for striking Bulldog Adam Cooney) and West Coast's Patrick McGinnity (three weeks for rough conduct against Crow Bernie Vince).
Westhoff's case will be heard at 5pm AEST.
