I had two non-retrieving dogs and with marker training and tug, I made them junkies.
If your dog loves tug, you had him retrieve the tug toy to start the game. With a non-tug toy, you "mark" when they first touch the object, then lift it, then retrieve it. You feed when you mark. It might take a few days for the dog to figure it all out, but it works with a food motivated dog.
To start, I had to tug and feed a lot. Now, my dogs love the game for the sake of the game and there is no food involved. Both dogs retrieve quickly and dependably and love it.