Your sentence is grammatical in English, so it is understandable/works as a translation. However, I think "he will not play" is better, as (I am quite certain) Esperanto demands the use of the future tense here and the literal translation should be favoured given that it is equally relevant.
There is a difference in meaning. In English, the use of the present tense to describe a future event indicates that one is scheduled or expected to perform the action (in this case, not to play tomorrow); the future tense makes it clearer that he was expected to, but can't.
I'm not (yet) sure how to make the same distinction in Esperanto.