Two young men are on a vast, level expanse of grass, and the man in the red shirt is catching the white Frisbee.
There are other people playing with them.
There are only two people mentioned, but many other people can play Frisbee too.
Two young men  on a vast, level expanse of grass, and the man in the red shirt catching the white Frisbee doesn't mean that there are other people playing with them.
Just because two young men are on a vast, level expanse of grass, and the man in the red shirt is catching the white Frisbee, doesn't mean there are other people playing with them.