If you are a Super Admin in your club, you have the ability to mute members, which will remove the ability to post or comment from that member.

First go to your club page, and click on 'members' on the right hand menu:

In the Members menu, find the member you want to mute and click on 'action', then in the dropdown, click 'mute':

Muted members who try to post in the club forums will receive a message that they are no longer allowed to post:

If you wish to unmute a member, you can do so by going back to the members menu, and in the same dropdown clicking 'unmute'

Other than the message when they try to post, members will not receive any notification that they have been muted or by who.