To go a little further in the line of questioning, ask the coaches if there are any existing walk-ons (non-athletic money players) on the team. Theoretically, they could already have 3 or 4 players, which when added to the 27 scholarship players would bump up the total to 30 or 31, leaving room for only 4 or 5 more walk-ons.
It's best to be as specific as possible with your questions and to phrase questions in as many different ways as possible to make sure you get the answer you are looking for. For example, when we were conversing with a program in the fall (which my son did not end up going with), we asked in an email, "Could you give us a thumbnail sketch of middle-infielders expected to play for (the school) next year?" The coach wrote back, "you ask about expected infielders to play for our team - i assume you mean spring of 2008?" He then proceeded to tell us who he anticipated starting in the spring of 2008, which was all juniors and seniors. This was NOT the answer we were looking for. What we wanted to know was how many '08 grad middle-infielders was the school planning to bring on? How you phrase the question is so important.