Sounds like he's missing the rest of the playoffs. I don't like the circumstances of this, but do you figure this makes him more likely to seek a multi-year deal this Summer?
He should still get max offers from Boston, New York, Lakers, and others. Perhaps he extends in Cleveland, but it would probably be unwise for him to opt in for a 1 year deal with such uncertainty about his health next season and how that could impact his free agency in 2016.