Is this possible with linux network programms/utilites ???

I have IP address of our Clan server, for "Jedi Knight: Jedi Outcast" game. I can connect to it ONLY through the game(this means - nmap can not see this port). So the question itself: is it able to monitor this server as I'am in there ??? I simply want to listen these server's messages. Is it possible ? -- -- Jedis are alive --