Error with NRPE mode

Hi,
I’m trying to use this plugin with NRPE but I’m getting a strange error :

Your PHP installation appears to be missing the MySQL extension which is required by WordPress.

When I run the command on the remote host, it’s working fine. In my nrpe.cfg I’ve defined the function as follow :

command[check_wp]=/opt/libexec/check_wp_version /web/wp

Any idea of what should be wrong ?