https://www.si.com/vault/1981/10/12/826014/the-courting-of-danny-ainge-a-jury-ruled-that-his-contract-with-the-toronto-blue-jays-was-binding-but-danny-said-baseball-was-out-and-if-red-auerbach-has-his-way-the-boston-celtics-will-be-in

I also saw another one indicate that his inability to hit the curve ball was indeed his problem.