Despite feeling fine physically, Kuo had recently been struggling with his command. He spent three months on the disabled list two years ago, and says he had a bout with what is known in the baseball lexicon as "Steve Blass disease" (referring to former MLB pitcher Steve Blass and applied to talented pitchers who inexplicably lose their ability to accurately throw a baseball). He recovered from that episode of loss of command, and the Dodgers are hopeful that he will return to pitching again in the future.
For most people, being disabled by an anxiety disorder is not as obvious as being put on a "disabled list" at their workplace or in their home life. But about 4.1% of adult in the United States are classified as having a severe anxiety disorder, and like Hong-Chih Kuo, some of these people are unable to work due to anxiety.