Profile SSL Client

Sounds like your pool members are listening on 443 and are expecting an SSL connection. If that's the case you will also need to add a server SSL profile to initiate SSL to the pool members. You can just use the built-in server SSL profile if you don't require verification of the certificate on the pool members. Or you can change your pool members to plain HTTP on port 80, which would not require a server SSL profile as you would be terminating SSL on the LTM and passing the traffic plain text to the pool members.