PfSense, Two external load balancers, Floating IP?

[hamex]

Greetings all,

i have a Debian machine act as load balance behind pfSense that sends request to web backend. if user requests static content, lb checks cache backend and so on.
recently i clone the lb machine to be backup but problem is i cant define those lb servers with floating ip in case of one of the lb servers goes down.
is it possible to send request from pfSense to LB servers by floating ip (or based on availability, connection)?

The network configuration in my mind is as follows:

pfSense (172.22.22.1)
–--------------------------------------------------------
                    172.22.22.9 (Floating IP)

|                                      |
Primary Load Balancer    Secondary load Balancer
    (172.22.22.10)                  (172.22.22.11)
              |                                      |

Web servers / DB / Cache

Thanks in advanced
-Hamed