I think that’s actually what I meant, since upon rereading it my use of the phrase “head up” seems bizarre even to me.
Sorry Ignatz I was being sloppy.
BTW my question was specifically about the use of ‘heads up’ as a noun rather than a verb. It was one of those times when I came across a phrase which was new to be several times in a short space of time. I’m surprised it has such a long history, but then when I mentioned it to Ponster after starting this thread he said - oh yeah, when you’re playing sport it means pay attention … you know folks, sometimes fighting ignorance begins at home 
Yeow. Now I can add one to my collection of joke names; Ed Zupp!