Alan,
I'm not familiar with the injection you described. With beef, I prefer a savory sauce/glaze/rub/injection, but that's only my personal preference. Were it me, I'd probably opt for a mix of good, no sodium beef broth, herbs (thyme, rosemary, etc.), garlic, onion, mushrooms, salt and pepper. simmer to infuse the liquid with flavors, strain and inject. You could also be a little wild and add a splash of Madeira wine which pairs well with beef.
Paul
