Disable my own creatures in play

Delver01

We can disable cards in hand to prevent them from being cast. It would be nice to be able to disable your own cards on the field; either to avoid wasting creatures against a 1'st strike / deathtouch creature or to more strategically pick your blockers. I don't see too many balance issues, as it would come at the cost of losing that creature's attack. And wouldn't be hard at all to code.