Eh, as one that was injured in such a way that it still affects him - blown out knee - I would say give them time to come back and be ready. I rushed it at first and strained my knee again, then had a sudden death in the family, but all that time I practiced what and how I could and went to class when and how. (Hell, after surgery, when the pain meds wore off I would rehearse all my forms in my head to distract myself.) Once they are back in ready shape, as long as they are working to THEIR limits, I say test them. And I fully admit there is some bias here on my part.