Yes, at this point in time it is difficult to determine a "Friends" or others playing status. This has been one of the #1 complaints. My suggestion...
Contact customer support. Request that with the next update they provide an improved means of showing a players availability to play a round.
From a programing point of view, this should be rather easy. To see how, simply look at your settings and under "General", add another bullet point or points. Someone correct me if I'm wrong.