Patrick Saunders has an exceptional profile of Tyler Matzek. The root of Matzek's pitching troubles appears to be performance anxiety. Interestingly, but unsurprisingly after thinking about it for a moment, this was something that began in late 2014. His excellence on the mound late that season created additional pressure to not just succeed in the same manner, but to exceed expectations the following year.
Based on a conversation with Matzek at his home in southern California, Saunders presents a great deal of statements from Matzek about the pressures of pitching professionally. His words access is the fact that baseball is designed to defeat everyone who plays it.