Being out there in full view of every body is an experience all in itself - then add the game on top of that.. and no wonder guys start breathing deep.
Here's a simple practice routine or drill to help you manage.
Sit in view of a clock or focus on a wrist watch and for a 60 second time frame do this:
(1) control your breathing INWARD with a nice easy pace for the first 5 seconds --
(2) control your breathing OUTWARD with a nice easy pace for the next 5 seconds --
(3)control your breathing INWARD with a nice easy pace for the next 5 seconds --
(4) control your breathing OUTWARD with a nice easy pace for the next 5 seconds --
So, after a 60 second spread - you've controlled your breathing INWARD and OUTWARD in 5 second segments each. And although this may seem like a peice of cake - your first try will have you breathing INWARD quickly for the first two seconds... then holding your breath waiting for the next five seconds to exhale. This drill is all about controlled INWARD and OUTWARD breathing... smooth and easy for the entire 5 second time spread. Concentrate.
After the first try of this drill, you might be a little light headed. So prepare yourself. But, your only doing this excercise once a day for only one minute (60 second) so it shouldn't be too bad.
What you will achieve, in time, is a breathing discipline that is controlled and well managed. Also, you'd be amazed at how calm you'll be even in the situations that cause you concern.