That is a really interesting story! My parents have two shelties. One of them LOVES to play, and the other wants to play, but doesn't know how, so he stands and watches the first one playing barking the whole time. But it's fun for him.

Maybe first you would get the two dogs to get along? Like do something calm with them, like petting, or feeding them treats together, or putting their bowls near by, and make them more comfortable with each other. Maybe once Sheltie knows Poodle he will want to play?

I've never met a dog who didn't want to play.. sorry I can't be more help!