Is there a way to insert a HOST header in an HTTP 1.1 health monitor request?

I'm trying to create an HTTPS health monitor that verifies the same URL path (to an image file) for multiple pools. I'm trying to find a way to insert a host header of the pool members IPs being monitored. This is simply an attempt to create a generic health check that can be applied to many pools. HTTP 1.1 requests require a HOST header. A null value (Host: ) is valid unless the HTTP server requires them for virtual hosting, which is the case. FQDN of the virtual servers should not be used in this case because they are WideIPs (BIG-IP DNS) for datacenter failover services. Both virtual server and pool listen ports are HTTPS.

Leaving HOST header blank does not work: GET /path/image.svg HTTP/1.1\r\nHost: \r\nConnection: Close\r\n\r\n

Is there a way to insert the pool member IP in the GET? GET /path/image.svg HTTP/1.1\r\nHost: \r\nConnection: Close\r\n\r\n

Of course, this would have to work for multiple pool members. I don't think there is an easy way to accomplish this within the health monitor, but worth asking. Worst case, I have to create unique health monitors for each pool using the virtual server IP in the HOST header.