I solved this using Rebecca's solution and also by keeping all fetch & tug toys up out the way when we are not using them.
The only toys I will throw for a real game are kept in my control, and the only toys I will tug with for a real game are kept in my control. The new pup also has his own game, which we call "Gonna get a PUP!!" where he carries his tug toy around and I chase him. That toy is restricted-use only as well. The dogs are welcome to bring any other toys to us for us to toss once or twice or to tug on once or twice but they know the real game will not happen without the real toys.
When my dogs want to play ball or play tug, they go stare at the out-of-reach toy box. The older dog will give up and lay down and sleep--near the toy box. The little guy does not have free run of the house yet so he is easier to deal with.
We also have a routine here. We throw the ball after we walk/jog (only older dog runs with me), and we walk/jog at certain times during the day. I did not want my dogs relying on specific times, so instead they are allowed to expect activities to follow other activities. (Fetch follows walk which follows me working at my desk for a few hours).
Finally, we have a command here called "All DONE!" and we hold up our hands to show they are empty. This means, the game is OVER. We do not EVER allow one more throw or whatever after we say "All done."
I got this last idea from my horse vet, who has a border collie named Vern. Vern is a fetching fool. If you are tired of throwing his stick, pine cone, frisbee, ball, whatever, you say "Leave it alone, Vern!" and you have to say it like you mean it. After you say it, he goes to someone else. Once he tried to get my horse to throw it when we ran out of people.
Allie, Tess, & Kipp